Do you mean they are as the Jam Host said "Rate for Rate" or do you mean this "It's alright to ask someone to play your game if you've played, rated, and gave feedback for their game"
No it is not rate for rate, and of course it is alright asking people to rate their game after they themselves have played commented and rated. What I am saying is that it is not alright when the person consistently only uses around 1min (if even any time) on a game, provide a quick comment as if they have played the game properly and then repeats that process as fast as possible to get ratings for their own game.
This post wasn't actually specifically targeted towards you, it was another person I noticed, though there might be others doing the same. Actually I have checked out your comments and you seem to be good, can't actually see what should be wrong about them, you provide feedback specifically for the game that isn't just first impression and it is obvious you have played through them. Don't worry you seem to be just fine :)
Don't worry about it, these people seem to be doing it intentionally. I am actually impressed about how you have gone through so many games already and provided proper feedback, please don't let my post discourage you or change what you are already doing, it was meant for some completely different people