Your sentences and grammar were not correct. The edit made several corrections.
It's not OK to change the style of a post just to change the style, however. The editing page says:
HOW TO EDIT
► fix grammatical or spelling errors
► clarify meaning without changing it
► correct minor mistakes
► add related resources or links
► always respect the original author
If you're not doing any of the first four, then the fifth (respect the author) is the most important thing left. It trumps searchability and other aspects that may contribute to the "success" of a post.
I think badp is saying the same thing, since he's talking about grammar, formatting, and quality. But I wouldn't agree with "Yes, it most certainly is [OK to change the writing style]" in the absence of those other concerns.
I would take partial issue with the first edit that subbed in an exclamation mark where you hadn't put one (which was reverted by the next edit) since we shouldn't inject fake emotion on someone else's behalf, but on the whole it was an improvement. Lengthening the sentences wasn't purely cosmetic, for example — it makes it more readable.