People who put outfits on their dogs for pleasure - I wouldn't do it, but it's harmless so YABU there, along with the other novelty items so long as they are safe for them to eat/drink. Having seen how rawhide is made, I would rather cheese grate my own eyeballs out than feed to my dogs but then I am a neurotic dog owner
People who say their animal NEEDS extra clothing do really, really fuck me off, because most of the time they don't need extra layers.
We go outside and need a big thick coat because it's four degrees, but our hairy counterparts do not have the same basal temperature as humans, they do not need the same layers on - when they are exercising it is inherently bad for them to become too warm. If you have a healthy dog and you are looking after them properly, they absolutely should not need extra jackets on.
I have a horse who I bought two years ago who needs a lifetime of additional management because some mindless idiot was over rugging him as if he were a human.
Animals manage through Homeostasis - over rugging prevents them from sweating and heat loss in the usual way and leads to heat stress - in the case of my horse he broke down and it lead to multiple colic incidents.
It is much better for an animal to be too cold for shorter periods than too hot.
I'm sorry that's a rant but I see so many people walking their dogs with rugs on and I just wonder whether they are aware of the damage they are doing!