You know, for all the heat the edition wars generate and all the bile that gets spewed, I've learned a lot from reading and participating in them.
Not everyone is a dyed-in-the-wool true believer. I'm a 4E player and DM, but the way I argue in some of the edition war threads, you wouldn't know it. While the system as a whole works for me, there are a number of places where I disagree vehemently with 4E's designers and I'm not shy about saying so. It's nice to find other people who have the same problems with the system I do, even if we disagree on whether those problems are deal-breakers.
And threads like "What did 4E get right?" encourage cross-pollination of ideas between the various camps. D&D has a long tradition of house-ruling and kit-bashing, and I believe every edition has
something to offer almost everyone--some mechanic or concept that's worth yoinking for your own game.
Then, too, people's minds change. For example, I used to take it for granted that 3E was just an all-around better game than 1E or 2E. But there are some very persuasive posters on this board arguing for the merits of TSR-era D&D, and they've reminded me of some of the things those older systems did well--to the point that I would now be quite open to playing in an AD&D or BECMI campaign, and maybe even running one (heavily house-ruled of course).
Finally, there's this simple fact: The more people play my edition of choice, the bigger and more diverse that edition's community becomes, and the easier it is to find new players. So there's a definite incentive to recruit.
These are some legitimate reasons for starting this sort of thread. Of course, we all know the real force driving edition wars is nothing so high-minded. When you put a bunch of intelligent, articulate, and opinionated people together in one place*, it's inevitable that half of them will immediately set out to explain to the other half in great detail why Everything You Know Is Wrong.
[size=-2]*Dumb, incoherent, opinionated people will do this too, but they won't be nearly as entertaining.[/size]