I can't see your edit anymore since the OP rolled it back but @slhck has shown you that it was indeed invalid. The question does not seem that bad to me either so I don't understand why you are making a big deal out of it. Granted it is badly written and could use a copy edit but the main question is quite clear:
So my question is, will the video card (GT720M) on the laptop perform better at a lower resolution than it would on a 1080 resolution?
As a general rule, the OP has the right to keep their question as they want. Most of us are pleased and grateful when our posts are improved but I can understand why someone just rejects what he sees as an invalid edit. Why should I go to the trouble of accepting and editing if I feel that your edit made my question worse?
As far as I can tell, you did not make a "minor" error, you radically changed the question being asked and, of course, it was rejected. That is no reason to downvote, you can either explain why you feel the post can be improved or walk away. In any case, you certainly don't downvote because someone chose not to accept your edit.
Now that I have seen your edit I completely agree with the OP. I would have rejected that as well. Your entire edit was a result of your (understandable) misunderstanding of the original question. As far as I can tell, the only change you made worth keeping was changing 1080x1920 to 1920x1080 and adding a space between a full stop and the next sentence. The rest of your edits did not improve the post, only changed its meaning. What would be the point of accepting an edit if improving it would revert the post to its original state?