Just noticed this as well. The check box in the options doesn't do anything either.
EDIT: I should add that my version might have some "low violence" restrictions. This could be relevant.
EDIT: (removed my dirty fix) as @alfred-valve suggested, lets wait for the fix :)
I assume this issue is related to:
http://steamcommunity.com/app/221410/discussions/0/864959088261471853/
and
https://github.com/ValveSoftware/steam-for-linux/issues/1336
don't do the cp, I'll have a fix released shortly, and it was related to the code changes for fixing gamedirs.
@alfred-valve: I removed my dirty fix :)
btw: my game is not low violence
HD and LV use the same code, I both broke (and will be fixing both :)
Thanks for the fast fix :)
Was CS also affected? A few minutes ago I heard from another user on the Steam for Linux chat that HD models were not working in CS 1.6.
CS also supports the feature. When I run the game I see the CZ models (if I have HD models checked in the Video tab of options, which is default). You only see what if you own both CS and CZ.
Since the last update (today) HL1 doesn't use the HD models (like for the weapons) anymore.