The story you've just read was written for someone very specific, using their very specific requests. It's not for you, the way fics posted normally are (theoretically) aimed at you as part of the audience. So if you don't like it, maybe you should STFU and cope.
For example, both my merry_smutmas and hd_holidays fics contain elements I wouldn't normally put into one of my fics, because the recipients wanted to see those things in their gifts. I wrote the stories for them, not for my own amusement or for a general audience.
I will never be comfortable with "don't leave concrit because you might hurt the poor ickle author's fragile feelings". Never. However, anon gift exchanges exist for the purpose of authors and artists reading and drawing for each other. If something they wrote or drew is not to your taste, and you aren't the recipient? Tough titty.
This has been a public service announcement brought to you in part by 8 gigs of unsorted music and a couple of giggling tomatoes.