By all means. There's been lots of discussion of this on Meta.SE, and as far as I can tell the only objection has been that people would abuse this to make 2 rep points at a time.
Which it would seem absurdly stupid to say, "No, please do not correct spelling errors in posts because we cannot afford to give you two rep points just for that".1 So there have been a few suggestions to swathe this affrontery, such as:
Edits could be approved as "too minor", such that the edit would be okay, but you would not get anything for it.
You could only receive a maximum of N points for edits done in M minutes.
Neither of these has been implemented though, which is probably for the best, since discouraging people from doing reasonable things voluntarily on a crowd sourced platform because we think we should show our lack of appreciation by saying this is not even worth 2 free internet points would be counter-productive.
One of the things from those discussions that I do take seriously, and it is the only reason I believe I have ever rejected an edit that was a legitimate correction, is that if you are going to make such changes, apply them evenly -- I think it is literally stated as "there should be no remaining errors", but this is a bit idealistic as not everyone notices the same errors, etc. The general point is, if there is a post that is full of obvious spelling, grammatical, and punctuation errors, and you submit an edit that corrects just one of them, then I or whoever may go ahead and correct them (or not), after I reject your lazy attempt to scam two free internet points ;)
That still could be taken as a dissuasion to fixing posts that require a lot of fixing, on the basis of "I don't have time to do everything so since doing something is not appreciated I will do nothing". Again, if it's me, and you've made a reasonable effort (which, with short posts, probably does equate to "fixed everything"), you have my approval.
1. And as per comments below, not all spelling errors are created equal and it might be considered important that we help stop the propagation of Rasbian vs. Raspbian -- how do you arrive at the "too minor" criteria now?