straight to the point, there are many things that ruin hentai or furry porn.

1. genitals
sure not everyone is lucky to have a decent or better shape and size whatever, but alot of artists just cant or dont draw the nicest of boobs or penis. so many weird shape and sizes get drawn

some with just balls or a dick and vag or a really odd one

worse is getting multi able dicks
and the worst hentai with a weird story is Dulce Report
alien slugs give women penis's

2. characters
i have seen alot of ugly males
not too many females but it can happen

both of these can be a major turn off

3. story
they can be good if they are written well
not too short, not too long. just right

4. Writing
porn isnt safe from plot holes and changing everything

5. Too much text
the less speech bubbles, the better
its a comic and what do comics have? pictures, images
too much speech bubbles mess up the story, makes things confusing of whos talking as well as bad and sloppy writing

6. Censores
i seen many types of censores
many types of pixels
black bars
and walls of light or silhouette
and more im forgetting

7. bad endings
its sad to see characters that dont get more time together and never weill, worse if its long, or short or cliff hanger ending

or they cheat and force others to cheat. not cool

8. extreme kinks
Rape
tentacles
Vore
Scat
arm pit hair
ass to mouth. Eww
cock and ball torture... yeah, that shit hurts
people have complained about cervix penetration

men feel pain too

9. Shipping
the internet and fandoms are WILD with this

anyone and anything paired with sponge bob
Shrek, sonic and more

Poor tails with: Amy, Rouge and jet the hawk? How about NO!

bad shipping.