Depends on the player. I don't think it's fair to classify that as bad. If they are having fun and at a table that is having fun, how could it be?
I don't want to say it is bad per se, but it leads to situations that are very much not ideal.
For example, many of my fellow players (and most DMs) do not know how underwater combat works. I can vaguely recall at least one situation where a player dove into the water to fight something, and had it explained that their weapon would be at disadvantage, and their response was "Crap, if I had known that I wouldn't have done that"
And I have heard that response a lot, players getting into situations, and only learning the rules for those situations in that moment, and having regrets because they were ill-informed of the rules. But there is a more insidious version of the same thing. Players being put in situations where they are struggling, because they are not using the rules that actually apply.
I've seen a lot of players have no idea how to deal with an enemy on a rooftop, not realizing that they can climb your average building at 15 ft a turn, which is easily enough to reach the top of most 1 story houses.
I get some people have fun without knowing all of this, but I also don't see a downside in encouraging people to learn the rules, because a lot of the time, knowing what you can do opens up options you wouldn't normally consider.
Sometimes people realize they aren't informed enough to have a legitimate opinion, or don't care enough to get involved one way or the other.
If they don't care, they abstain. Easy enough.
If you feel you aren't informed enough to have an opinion, then I personally see that as a problem, and you should definitely ask to be informed of the situation, rather than sit back and let other people decide for you.
Not necessarily. Social pressure is much more pervasive than I think you give it credit for.
Social pressure is a big deal, I know, but here is the thing social pressure to that extend represents a problem between the group.
If I have to limit myself and be very careful around someone for fear of upsetting them, then I cannot relax and have fun. I cannot make decisions honestly, because I fear for that person's reaction.
And, as I have lived most of my life that way, I can tell you it is bad. Constantly worrying about whether you are going to upset someone just by speaking your mind is a terrible way to live, and no way to have fun. And if someone feels that way at my table, I need to tell them they are wrong. We are all friends, it is just a game, and we aren't going to hold what happens at the table against them.
Because I want them to relax and unwind, and in that situation, they can't.