My reasons for this is because it would not put the person on the defensive by making character attacks ("if you weren't so lazy") and it opens up a dialogue for things such as why couldn't the person succeed the first time around, what was going on at the time, and how those obstacles could be avoided in the future. I would view couching my inquiry in that way as both constructive and productive.
However, I might see the fact that they're lazy and unable to admit it, as the real problem behind what's going on. My view might be that, if they could have a bit more humility about their flaws and be able to speak about them openly, without sugar coating things and making people pretend they haven't noticed those flaws so that nobody mentions them directly, then maybe they'd be able to address those flaws in a more direct way, and maybe it'd remove the bullshit screen that stands between them and recognizing that when they tell themselves they're not doing any reading tonight for their course, this is just laziness talking and not all the valid justifications that they give themselves and their friends politely agree with.
I think that facing the naked truth about yourself is about the most constructive thing a person can do. Maybe I see not just the laziness but the pride that's at the root of them being hurt when someone points it out, as big problems that stand in the way of their achieving what they want to.
I wouldn't bother speaking to most people this way, because I know they're not capable of responding to it constructively. So that's why, with most people, I've learned to either keep my opinions to myself and not answer anything (and shrug it off when they get mad at me for that and read their own things into it), or if I'm asked for one, I'll give it my way. If they wanted a touchy feely opinion, they shouldn't have come to me.
I can't talk for all NT's but for me, yes, I do have very frank and open discussions about my bad points on a regular basis. Whilst when I was younger I didn't take things as well as I ought to have, it's been a long time since I've got upset over someone pointing out a bad point I have... mostly cos I'm so used to talking about them directly and openly, that there aren't many that you could surprise me with to even
be upset over. And I have a sense of humour about myself.
I had a friend at school who was very sensitive about this kinda thing, you always had to couch things and sugar coat them for her. She was uptight and really square, and very unadventurous and had no backbone. She needed a job, and I had one at a video store, so she asked if I'd talk to the manager to get her a job. I said I wasn't sure she would like working there (she's an ISFJ), cos the atmosphere's quite boisterous amongst the mostly male staff, and the women there were pretty plain speaking too. But she said she needed the money and was tougher than I thought, so I got her the job.
She spent the first few months feeling ruthlessly mocked and ribbed all day long, thinking everyone hated her and was trying to get at her - she didn't notice that they spoke like that to each other too, and yet were all great pals, she was too busy feeling like the victim. She stuck at the job partly though needing the money and partly through not having the balls for the confrontation that "might" happen if she said she wanted to quit. I moved town and we lost touch for a while.
Next time I saw her, she'd completely loosened up. She was way happier and more relaxed, and had learned to laugh at herself good naturedly and allow others to do so too without taking it as an attack. She said on Facebook the other day that the most valuable experience in her life was working at that video store, because it taught her to stop pinning the responsibility for her subjective feelings onto everyone else. She worked at that store for over three years, eventually adapting and finding her feet and her confidence in herself, realizing that the others were just kidding around or offering what they considered useful information, and ending up area manager for a while. She's still in touch with those same people who she was so sure were nasty, mean and hurtful to start with, two of them were her bridesmaids and one is her child's godfather.