Cap, that comment was based on observing my mother and father. My father is an INTP 5w6 and by his own admission quite critical. I imagine that he would agree with the way you are framing this - that he is just noting objective truths - but through my mother's or my eyes, it is quite a lot of complaining/criticizing and very little appreciation. He says things when he feels like they need to be said, which generally correlates with when there is a problem that needs addressing. Consequently, he rarely says anything when things are running smoothly. If our home were NASA or a laboratory, then that would be fine. But it's a respite and a haven, and my mother and I desire it to be positive and supportive. There isn't a problem with dad pointing out what's wrong, but there is a problem with him not communicating appreciation or encouragement. It's the ratio that is an issue for us. Like the time I spent two hours cleaning the whole kitchen as a surprise for my parents and dad pointed out the single dirty fork I had just finished my own food with.
What is interesting to me is that my ISTP brother does not seem to share this problem. It may be because he is a 9, and more passive overall. But even he gets to the point of frustration with dad's criticism.
Maybe you should ask them why they think this? It seems like an odd occurrence.
Maybe you are using one example to defeat the many. Not saying there isn't a lack of positive support, but I don't think what you've described is common behavior. I don't go out of my way to point out criticisms like that, that sounds more like xxTJ territory. I don't just randomly point out "objective truths," someone would've needed to ask. Also, are you an extrovert? ExFx would obviously be more "needy" in the attention department than an introvert, though introverts complain as well. It all boils down to whether you can legitimately appreciate what the INTP considers showing affection (actions, usually, maybe touch, not so much words). The INTP may also be particularly proud of their method of showing affection, considering it more meaningful, and therefore even if they could change to something more typically demanded (words), they'd probably not choose to. They have a big problem with empty compliments. If that cannot be reconciled, then you'll have problems.
Also, I've seen those who meet the needs of those who want more words and more positive support, and it's almost like they are killing themselves doing it, and it seems to carve out a big chunk of their time, attention, and life, and it's strange that this is the expected norm. I don't think I'd ever be able to do that, or that I'd ever be comfortable doing that, even if I wanted to. It doesn't help that I get annoyed when people shower me with this BS. It means nothing to me. Do something to show that you care. That's clearly harder anyway. Words can so frequently and so easily mean nothing, but then again women fall for this BS all the time (BS when it comes from the wrong people). It's just strange to me. I don't know, maybe that's why the INTP has such little luck with women, and maybe that's why snake oil and other types who shower women with compliments, etc, pick them up left and right. On some level, I find it repulsive, and would rather not end up with women that are this gullible, or this needy, or this unable to appreciate what I'd be willing to slave over, but maybe I don't have a choice.
As for noticing the little things, I don't know. On the one hand the person worked hard on it and wants to be acknowledged (so hopefully it was worth doing, rather than something the other party doesn't care about), but on the other hand, I'd be annoyed if someone were to point out every single thing I did, or try to compliment me on it. Maybe that position has wired out such behavior from me.
I guess it boils down to the fact that you want to be showered with compliments and I love yous, whether you admit to it or not, and it's then about who would be able to provide such an environment, because I doubt that would be an INTP. Maybe some INTPs can live in an environment where their natural inclinations aren't appreciated, but if I were personally complained to like this, then I would think the relationship should end. Becoming more "supportive" than I already am seems impossible, and I'd probably talk myself out of it at some point, so I wouldn't bother. That is, I think this is one thing about myself (talking about me personally) that I wouldn't want to change, even though it's such a common complaint. I'd start looking for someone that cares about other things. And with this all, I'm not saying that words don't matter, or that compliments don't matter, or that I don't give compliments/support at all, I'm saying that if what's needed exceeds my ability to give, and it's that big a deal, then I'd bow out.
What I also notice is that in relationships where this is a problem, the other partner usually ends up cheating, or they end up with the victim mentality, projecting all manner of negative shit and hatred onto the other person. I don't think that's a workable environment. But what I've also noticed is that not all women are like this.
Some INTP+ENFJ relationships work, but did I mention that I think it's a bad idea? I don't think it's the best situation to get caught up in. But more accurate would be a relationship in which you are incompatible, or in which your desired methods of showing affection, support, are not aligned is not a good idea. What about the INTP? Does the INTP just not care, or are they happy? Showering me with compliments would annoy me, not backing up your words (rarely do I need verbal support) with actions would annoy me, doing things that you try to force me to appreciate when I actually don't care about them would bother me. I don't know. Maybe it's all about the women in these situations, because they are so convinced that they are delivering what the other party wants and it's their needs that aren't being met, but I think it goes the other way as well. Maybe it gets confusing or unclear because I don't go around complaining or being bothered by every single little thing, or maybe it's because I'm easy to please and low maintenance, or maybe it's because I'm a thinker, I don't know, but maybe the INTP is happy inspite of you, not because of what you are doing. This thing goes both ways.