The downside of this is because of the binary sense of behavior, there is a weakened sense of consideration toward the emotional reaction to statements or actions. When I act in a positive sense toward someone I want a connection with, I really genuinely do want that connection - but it's not an emotional sort of connection as much as it is an intellectual one. I only feel truly connected to a person when I know them entirely, and they know me entirely, and in this shared knowledge that we are invariably bound to one another (I think that's also why we tend to be not so good at prioritizing and censoring information exchange).
This sense of deep knowing (as in Stranger in a Strange Land, "grokking", a concept that I think most NTs understood at a deep level at first glance) does eventually turn into a strong emotional bond, to where we feel we can't live without that person, such as the quote in your signature. However, that's the endpoint of the relationship development. Once we've gotten to that point, we feel it's understood how each party perceives and feels about the other person, that each can be counted on for important things, and that full honest disclosure without softening is acceptable, because it's not going to change that person's opinion of you (the binary sense of positive/negative opinion of a person). At that point, that person has become a home base, and we've become a loyal colleague to the end.
Of course, at that point, the other person also starts to become a little boring, since we've figured out what makes them tick. As much as we like them, and feel we're better people for having them in our lives, we don't need to be around them all the time. The world's a big place, you know, and a lot of people are in it. So, perhaps we don't go out of our way to spend time with you anymore, because we have so much else we're interested in doing. Maybe a new project, or maybe a fun vacation that we didn't invite you to, because you didn't seem like you were having that much fun on the last one, though if you did and we read you wrong, tell us and we'll never not invite you again, even family vacations. I'm beginning to understand why that's hurtful - no one likes being left out, and it seems malicious even if the intent was completely benign. Empathy is certainly a trait that has to be actively developed in our type.
That being said, any time there's an emergency, something major, and by major I mean earth-shattering, where you absolutely need someone right now who will do whatever they can to make you feel better and to make the situation better, I can't think of a better type of person to have around than an ENTP. Without question we'll drop whatever it is we're doing (we're pretty good about that), and start hitting every resource we can possibly think of to make you feel better and rectify the situation. We'll stay until we've done everything we can think of, and once we feel like you don't need us anymore, only then will we begin to leave, but not before asking about a million times "are you sure there's nothing else you need from me?"
If that's not love, what is?