I have been rather generous with my flags, the most common reason is for tag spam. It annoys me when people use tags inappropriately hoping to get tokens that don't really belong to them by curators who don't read the content. What I've noticed is that these people, who are trying to optimize their return with as little effort as possible, really get angry with flags. They often threaten me, which leads to a mini flag war that I know I will win because I don't really care about some minor flags from reward pool rapists.
Why do people feel like they have a right to not be flagged anymore than I have a right to flag for whatever reason I want? Some people think it will scare people away from Steem. More people are scared away from Steem because they see crappy Technical Analysis trending or people playing guitars and holding cups of coffee.
Oh no, I lost a few cents I didn't deserve because I made some lousy post which people didn't like. I am never going to post here again and everyone is going to hate Steem because of it...
Glad to hear you are flagging. Without this, people would be abusing the platform left right and center. Since the ban hammer is almost non-existent, we need coordinated effort and support to clean things up.
I despite the argument of 'who are you to judge'. Well, I'm no authority, but if you don't want my flag, don't breach etiquette, don't abuse, don't troll. Steem would be a nasty cesspool if people could be as awful as human nature allows for. The rules are very lax in my opinion compared to centralized platforms where abuse isn't even possible. Here you just have some responsibility because there is no central authority to put their foot down.
It's nice that you aren't scared off by a little revenge flagging. I think that is worse than opinion flagging or random flagging.
Tag abuse is definitely an issue, but I think it is more related to Scot-tokens and tribes than to new Steem. However, fighting is easier than ever. It's good preparation for when SMTs and communities come out as they will need the tools avaliable especially if they hope to attract platforms and people who aren't already established Steem users familiar with everything.