> Someone who can wear an "M" can just as easily wear an "L" or "XL", but the reverse is very much not true.
It's that thinking that leads to skinny people (like me) having a lot of large t-shirts that they don't fit into. Just because it can physically go over your body doesn't mean that it "fits."
Agreed, there are always way too many M's, never enough S. Offering a one-size-too-big shirt is a great way to get someone to take the shirt but never wear it because it looks sloppy.
It's that thinking that leads to skinny people (like me) having a lot of large t-shirts that they don't fit into. Just because it can physically go over your body doesn't mean that it "fits."