Board games are just as much about design as electronic games. I vote for the allowance of board games in this community. Besides, many board games eventually become electronic either as a direct implementation or as inspiration for something else.
Game Development as a term refers to the development of all games as a whole. I'd say board (or analog) games should belong here just as much as digital games.
That being said, if people really wish to separate the two and there is enough interest for it, then why not just make a separate community for board games?
I think it's valid to talk about them here, too. The main difference between board games and video games is who enforces the rules. Videogames leave the rule enforcing to the computer, while analog games leave it to the players. Besides, there are plenty of board and card games that are ported to PC/consoles and vice versa.
I'm not offended by the idea, but I definitely subscribed here to hear about the electronic game development industry. So, my vote is against board/card game posts