I don't think anyone here as enough posts yet to warrant any accusation of “systematic” behaviour. You are a frequent user of Physics.SE, so you probably don't need the generic description that follows, but I'll leave it as a general note to new SE users on this topic.
Disagreement on SE is common, as it is in science in general!  It's even healthy in the long term, because it is a sign of diversity of viewpoints and results in better answers. The way it is handled is by comments, competitive answers and community voting. Flags are an orthogonal system, designed to handled improper content (off-topic post, spam, hate speech, bullying) or behaviour (less common).
In the beginnings of a SE site, the situation is a bit more complex: we all want it to thrive and we still have few users, so I tend to think that we do upvote more cheerily. Also, we don't yet have proper moderators to handle flags, so they are currently dealt with by StackExchange team members who might not have an overall view of the community and site (but of course, Big Brother is watching us!).
Now, regarding your specific question, we can only discuss specific behaviour. If you feel you have been smeared somewhere on the site, in a way that does not adhere to the SE standards and/or scientific discourse, please give links and we can discuss. I tried to dig a bit, and in the three cases where I saw your answers contested a competing answer was proposed, which seems like a fair behaviour to me.
 Actually, I consider that it is actually much more common on wide open sites like SE, because people with very different backgrounds and “academic level” will see things differently and they might answer the same question with very different viewpoints. Some people will be self-taught, some will have a generic undergrad-level understanding of chemistry topics, some people will be experts but only in a few topics, some high-school teachers might have a very broad knowledge but few practicals skills, and maybe people with a longer career behind them will have a very good sense of how things happen but not much experience in formalizing it. What I mean is that we probably want Chemistry.SE to be something like a big tent-style community.