There's a little bit of competition, and a little bit of competition is good...
Hi Emma and welcome to SFF:SE! I'm Praxis. I am a room owner for our chatroom. I was there when you posted this, and your post came up briefly there as Tango and CandiedMango wrote responses to you. I decided to wait a little longer to weigh in on this, mainly to formulate my thoughts properly and to see what others had to say.
I think the first thing I'd like to tell you, to answer your very last question, is that you are not alone. A few others have expressed frustration with the competitive aspects of the site very recently, although they did not do so in Meta (rather, through the chat room or through commenting).
This doesn't mean that the site is too competitive, but only that there is competition. Whenever there is competition, people fall on either the losing or winning end of it, and that causes problems, as I am sure you are well aware.
Benefits of the reputation system
Having a reputation system (yep, we keep score) gives people an incentive to answer questions. I am saying this because you are particularly interested in the effect of competition on newer users. While competition can indeed scare off some newer users, it is mostly a boon to them, as the promise of rep means that people will step forward to answer questions, including somewhat tedious questions (which no one would think twice about normally) and difficult questions (which may not be worth the effort otherwise).
Personally, I enjoy answering for the sake of answering, and acceptance of an answer is more of a goal for me than reputation (because I feel good when I know I have helped someone and solved a problem). But I understand the value of reputation in connecting new users with questions to established users with answers.
When a new user gets a good answer, they are more likely to stay. Quite often they never return, but that's usually because they got the one thing they needed, not because they were scared off.
Main versus Meta
You are a curious new user who has been poking around in Meta, reading comments, etc. — that's great! We get many new users each day, and most don't make it so far into the site. Many ask a question ("I'm looking for a book I once read..."), get an answer, and have no immediate need to explore Meta. In a sense, Meta is like a workshop where experienced users go to discuss aspects of site operation. Sure, some new users make it there and even have a question to ask but it's not the norm. By the time most get to Meta, they have usually decided to stick it out and have been exposed to a variety of comments of different styles and moods on the main site.
If that particular comment had been made on the main site, it could be removed as being off-topic. Here, it is on-topic, even if it is (perhaps) unnecessarily self-focused.
You shouldn't be afraid to get on anyone's "bad side" — you likely won't and there are mechanisms for dealing with that if you feel you are being targeted unfairly in any way. You will also find that someone you weren't getting along with one week will be sticking out their neck for you the following week. People get over things here very quickly!
Perhaps the real moral is to not draw too many conclusions from one comment from one user with little context.
You should aim to be the user that you want to be. If you spend enough time here participating in the way that you want to participate, people may start to emulate you, for better or for worse.
You can even make it your pet project to welcome and support new users, to explain the site and community to them. The site is what you make it to be. The arrival of one new but active user can affect the site considerably. You actually have incredible power to steer the site, if you want it (and are willing to earn it by keeping up your participation).
Again, welcome to SFF:SE. Stick around, don't be afraid to speak up, and don't be afraid to lead by example.