You wrote such a big post about such obvious thing, I am just surprised how you could find so many words for explainment of the most simple way: find a topic, reply it if you know the point. That's all!
I count my own comments just like you have said, but why I still not get a Merit then?

I think other users feel the same about their posts. So, your strategy doesn't work in many cases.
That's the fact. Recently, after launch of merit system, users tend to write as long as possible in order to catch attention of higher rank users, which in turn might help them to get merits.
I don't want to refuse their efforts, hard works and of course their time spent to those ones. However, it doesn't make sense.
As you pointed out, the contents in the OP can obviously describe or paraphrase in briefer sentences. I think it's enough.
Too long sentences (this one is extremely long) take more time to read (if we can have shorter one, but still meaningful, why not?). It's unnecessary.