cOrrect CAPitaliZation and grammar is eXtreMely impotrtant to the understandment opf your posstes, aNd, quit frenkly, iF iT b0thers u that other person took a times too edIt and improvo yours poster, you preBably should post not here be.
More seriously, yes, such edits are absolutely encouraged here. We aim to have a higher quality than what you find in YouTube comments and Yahoo! Answers posts. Which is not to say that your post is in any way comparable to that sort of egregious example, but only to point out that yes, even small things like capitalization and minor grammar tweaks are important. Anything that makes the post clearer, easier to read and more correct is a good thing.
Also, many (most?) people who post here are not native speakers of English and, very understandably, will make mistakes when writing in the language. We don't expect or require everyone to write in 100% correct English here, but that's why other users have the right to edit so that such issues can be fixed. And yes, incorrect grammar is absolutely a problem that needs to be fixed. Not because we're "OCD" or "English teachers", but because correct grammar is essential for communication in any language.
The important point is not to take it personally. Such edits are not in any way an attack on you. They are simply part of a collective effort to improve the quality of the site's content. If you can't be bothered to write USB instead of usb, that isn't a big deal. However, if someone else cares to take the time and 'correct' that, it does no harm and does do a little bit of good. I don't see why you'd object. I remember being very impressed back when I first joined Stack Exchange and saw that some helpful user had gone through my post and corrected all capitalizations I had been too lazy to use. My reaction was to thank them in a comment and that sort of thing was one of the major reasons I stuck around. The internet is already full of examples of writing similar to my first paragraph here. Let's not add to them.
Now, having seen the edit which, I assume, prompted this question I have to say that every change made improved your post. Those weren't minor changes, you had written something that required editing to fix both grammar and punctuation. The edited post is much clearer and easier to read which increases your chances of getting an answer since it makes it more likely that people will read it.
So, yes such edits are both encouraged and expected here and are a very large part of the reason the Stack Exchange sites have become so popular.