Why do men's clothes come up so small these days.

Depends on where the shirt was manufactured/brand or something. Usually it's the sleeves that are smaller/shorter these days.

 

a lot of it has to due with the way the clothing is designed
more and more the trend is more towards "athletic cut"
which is more slimming and fitted.....

 

I can't really speak for men's sizes--don't they go by an inch measurement anyway, waist and inseam? How could that manage to change the sizes?

Women's clothing, however, has changed sizes over the years. Vanity sizing, it's called. What used to be a 6 is not a 4, a 4 a 2, a 2 a 0--we want to feel slimmer, without the effort required to actually do so, right? From the wikipedia article (obviously a legit source):

"Size inconsistency has existed since at least 1937. In Sears's 1937 catalog, a size 14 dress had a bust size of 32 inches (81 cm). In 1967, the same bust size was a size 8. In 2011, it was a size 0.[4] Some argue that vanity sizing is designed to satisfy wearers' wishes to appear thin and feel better about themselves.[1][2] Designer Nicole Miller introduced size 0 because of its strong California presence and to satisfy the request of many Asian customers. It introduced subzero sizes for naturally petite women.[1] However, the increasing size of clothing with the same nominal size caused Nicole Miller to introduce size 0, 00, or subzero sizes.[1] The UK's Chief Medical Officer has suggested that vanity sizing has contributed to the normalisation of obesity in society.[5]"

Kind of interesting that size 0 was "introduced at the require of Asian customers" ha!

 

For gay reasons