To be frank about it, yes. There are a certain cohort of people on this site that have their heads so far up their tails they're at risk of recursion. Yes, there are some generally self-righteous commentators who pull apart an answer or question they don't properly understand and seem to troll the site more than provide any real value.
But in all fairness, that is also a reasonably accurate description of my workplace. Perhaps even my extended family. Despite this, I have remained on the site since starting just under 2 years ago at the time of writing this (Sept 2019), I keep going to work and I don't (mostly) try to avoid family gatherings. Why?
Because your first premise (a) isn't correct. Sure, these people exist, and there are days when they seem to be the most prolific contributors to the site. And sure; there are days when that's all you see in your comment block and you wonder why you keep doing this. But you need to remember 3 things here.
1) We don't encourage 'well done' comments
If a question or answer is well formed in the first place and there's nothing you can add, we don't generally encourage people to post 'attaboy' comments because it would detract from question or answer directly. We expect answers and questions to be of good quality in the first place and as such the lack of support comments is a reflection of the high bar we set for ourselves.
2) Comment Fields are short
Some of the most useful comments I've received on the site have at first seemed to me to be terse. When you only have a couple of hundred characters to work with, brevity is important but it comes at the price of a lot of 'softening' language that would normally assure the recipient that the advice is constructive and discourage taking the comment personally.
3) We tend to be biased towards believing our work is of high quality
This is a trickier one, but I've learned it the hard way directly on this site so I would like to share it with you. When you do get a '+1, great answer, just a small nitpick' comment, I personally don't feel as much of a positive emotional response to that as I do from a 'you don't know what you're writing about' comment. I already tend to believe that my answer is good because otherwise I wouldn't post it. So the negative feedback comes as more of a blow; just saying. Sometimes, I believe the criticsm to be helpful and somewhat well founded. Other times, not so much. I have probably guessed wrong in both cases. Point is after a while, you learn to roll with it.
In any event, I have been as guilty as anyone else in recent times of biting back when I think I'm being trolled or I'm dealing with the self-righteous. I'm trying really hard not to respond to these and just ignore them. Consider me a recovering responder who lapses every now and then.
Which brings me to the whole point of this missive. The answer to your (b) question is yes, there IS something we can all do. Just ignore (or in severe cases, flag) comments you feel are unhelpful. In the early days I tried to take everyone's feedback into account and edit my answer so as to avoid negative feedback, and all that happened is that I twisted my answers into something that didn't get the neg votes changed and restricted my ability to get more upvotes.
On this site, whether we like it or not, and largely due to the time limits after edits in which people can change their vote, once you have neg votes, they're there to stay. So, if the comment is helpful in your opinion, by all means edit your question or answer to reflect the new information. If it isn't, my advice is to simply ignore it. If the votes on your answer in particular are ALL neg votes, delete and move on. We've all put up an answer which hasn't been worthy of us in the past, even (if not especially) me. Don't let it stop you from contributing in the future however. Just delete the ones that are tanking and get on with providing new questions or answers and learn from the experience.
To be frank, I believe that the vast majority of people on this site are good people, trying to help out others, sometimes by providing frank and fearless advice to the posters who contribute in prime. SE can seem like a critical and unforgiving environment but it's important to note that the very design of the site, and the standard to which we hold ourselves, makes it far more likely that comments will sound negative. Your positive feedback is the rep score of your contribution instead. So; while 3x neg comments may hit you harder emotionally than a score of 30+ on your contribution, the rep score is actually the stronger indicator that your contribution is valued.