I can remember that in DOS1 it was quite possible...
You basically encapsulated most of my thoughts as well. To reiterate, surfaces do plenty damage if you are walking around, but mobility kind of negates it a lot of the time. Also there are curses all the damn time. I'm playing through with magic party now and I'll try use bless and source vampirism more, seeing as how the latter was always blocked by magic armor with my physical party.
Also in my experience so far, if you have a magic party, surfaces are quite a big deal in spreading debuffs! It's easy to get their magic armor down and from there to poison, shock, burn, etc, helps a lot with the damage.
In short, if you play physical party surfaces are just an inconvenience, but not really. If you play magic party it becomes much bigger part of the game.
