Coming from a player who predominately does little pvp on MCD, I enjoy the lava pits. I feel a majority of people who go to chasm are not prepared for a large scale fight between factions (and if your computer contains half a potato inside of it like mine, chasm is not fun to pvp in).
I understand everyone knows their risk when they drop into chasm, however, if I open pit for an hour and farm with a few of my faction members for the first 40 minutes, I feel the lava pits give me a chance to keep another rival faction from coming in and taking the stack of souls that has been farmed by myself and my faction members. I say this with the assumption and from my experience that 2-3 people drop into chasm with full pot load outs that easily outmatch the setup of players farming.
The clear counter-argument here is that farming players should plan accordingly for such fights. The first issue I have with this is from personal experience and from watching Lurnn. If you solo kill a boss, you are guaranteed 3-4 inventory slots of fragments, an occasional full soul drop, and rarely an Axe of Famine or Summoners staff. That means always keeping 4-5 slots open for picking up items. Coming back to watching Lurnn, I observe him dropping pots in order to pick these items up. This gives me the assumption that he will always have an entire inventory of potions ready to pvp with and I assume this parallels to his faction members. This is not realistic for players who are farming souls.
My second counter is the lag aspect of pit. Even if I was forced to 'suck it up' and fill my inventory to the brim with potions, the pit is still located at spawn which hosts the peak point of lag for most players on MCD. For me personally, it does not really matter who I am pvping at spawn because I will lose the FPS battle before the pvp battle. So when I plan accordingly for fights, my plan is to run to the lava, rather than die before I know what happened.
This is just my opinion on it, sorry it is so long-winded. I'll be more than happy to try and answer any flaws/holes in my logic.