I had to wear a sticker when I visited the Guggenheim and I felt sort of silly.
It was quite a large sticker and had warnings about staining certain fabrics.
I am not Ms. fashionplate but I think alot of individuals especially those with
nice clothes might resist wearing a big ol' sticker on their Chanel
(exaggeration intended).

I can't think of any museum that I have been to (except aquaria/zoos) which
used a turnstile.

Just my 2 cents