Random battles are an archaic way of handling enemy encounters. I can tolerate them if the frequency of the battles is low, but honestly, in this day and age it should be done away with. I find that random battles tend to deter exploration. I mean, you might see a treasure chest across the room, but is it really worth 5 minutes of fighting just to get some crappy potion? Usually not.
Also, random battles really piss me off when I get lost. Sometimes, after a long battle, I might forget which way I was headed. Once I realize I'm going in the wrong direction and turn around, I have to fight another battle.
Random battles also just don't make any sense. It's completely illogical why you can keep getting in fights simply by running around in circles in an empty room.
Anyway, I see random battles as being the lazy way out. If they actually had to place enemies in a level, then that would require some actual thought and level design. They would actually have to spend some time deciding where to place enemies, which enemies to put where, etc...
I couldn't believe IGN's review of TOS actually complained about being able to avoid random encounters. "Oh noes! Making the game less tedious is the terribles!"