Olympic Arms, one of the earliest makers of AR-15 clones, has announced that it is closing its door at the end of February. Long before there was a Stag or Daniel Defense there was Olympic Arms. According to their website's serial number history, they began making their ARs in 1979.
I don't know if this a general trend or merely an older company that was eclipsed by the younger, more innovative companies. I would tend to think it is the latter and not the former.
I do remember my friend Milo being all excited when he got his Olympic Arms AR-15. I had an email from his describing how he and his son John carefully broke it in. I'm guessing this was during the early years of the Clinton assault weapon (sic) ban.
Here is the announcement from the Olympic Arms website: