Not a matter of right or wrong, it's a matter of is it wise or not.
If too many people keep too many big fish and all you will have is a bunch of small ones. Me, I like there to be a mix when I go fishing so many of us encourage folks to put the big ones back and if you want to eat a few, keep a few small ones.
Heck, ask any DNR biologist. I bet he will say the same.
Besides, them 10 to 12 inchers taste much better.
I have seen trout streams where nothing but 5 inchers because the limit was 10 fish 7" or over. A waste of time to fish it.
That is my story and I'm sticking to it and what it's worth and 50 cents still won't buy a cup of coffee!