1. A higher bar for comments based on age of account and karma.
2. A limit on the number of comments from any individual account, e.g. each account would only get one or two comments. The idea being "get out your point as clearly as possible in one message", because you won't have the option for endless back-and-forth (and potentially escalating) debate.
To be fair the corollary is that you already know what you are getting from this place so probably sticking to purer tech topics on a tech accelerator's forum is fair enough. Interesting the these things overlap of course as I suspect will become ever more common.
You may already know this, but you can turn showdead on in your profile, which lets you see dead posts easily.
I will say that 95+% of the time the dead comments I see have earned their status, but I could see a case for decreasing the grayness for downvoted comments or making it a configurable option.