Your idea has been suggested by many members previously (including me), but until now it doesn't happen. IMO it's because :
1. No moderator with sufficient altcoin's technical knowledge which means moderator can't identify which post is FUD, troll or not
2. Many members would pretend they have in-depth knowledge, even though all they do are throw some terminology or details from other website/whitepaper
3. The board would turn into announcement/promotion board where each coins claims they have best technology
Besides, few of non-bitcoin/altcoin technology already discussed on
Development & Technical Discussion.
Things might be different if this suggested-board have some restriction such as signature disabled or minimum rank (Jr. Member / Member).