It goes straight to his head
Imagine if Spock’s ears worked like Barf from Spaceballs. Just moving them around all willy nilly.
Andorians have the "all willy-nilly" covered
https://external-content.duckduckgo.com/iu/?u=http%3A%2F%2Fmedia.tumblr.com%2Ftumblr_m2zy4b9nYg1qhwont.gif&f=1&nofb=1&ipt=0c57625c41c67820dbacce58374f51404a7bb74a36bc3a8ac9db2ac5ec0c2706&ipo=images
You'd think by the 23rd century there'd be a pill for that.
Heineken ... illogical indeed
So his ears must remain turgid to be upright. And his blood is green. Are we sure Vulcans aren't plants?? Maybe an especially intelligent offshoot of a jade plant?