Not everyone has time to know exactly what's supported by every combination of hardware and software they use or might use in the future. Personally, I came under the impression that the major filesystems in linux (or ext4 at the very least) "supported" trim years before I actually got an SSD. When I did, it didn't occur to me that I'd need to provide an option to mount for it to actually use said support.

News to me, and I've been using linux since I downloaded SLS floppies from a BBS. As it happens, I'm running Samsung's "flash friendly filesystem" (f2fs) on this machine; I hope I don't need to make sure _it_ is issuing trim instructions.