Why not? 
Not all posts at WP.org forums tagged buddypress have issues specific to BP. In many cases, WP.org moderators have referrred posters to our forums here. In some cases, I’ve referred posters here to multisite forums or third-party plugin and theme forums in WP.org when appropriate. And many plugin and theme devs have their own forums as well.
If your post is unanswered after 24 hours, feel free to bump your topic. 99.9% of those who help out here are volunteers/developers living in different time zones.
‘Tags’ are added by users it’s their decision to do so not WP support to run a specific support area for BP, in other words there aren’t support forums in two places really, it’s just unfortunate that people would ask BP specific question on WP support when this dedicated site exists.
Ok scrub my comments, WP does what bp does here for plugin support, so Yes! it is unfortunate that two places exist to support one entity.
Maybe I do it all wrong, but I’ve found that on WP when I have an issue with a plugin, I end up going to the plugin page (e.g. https://wordpress.org/extend/plugins/buddypress/) hoping to find answers in FAQ, notes etc. If I don’t find answers there, I click on “Forum Posts” link on the page, which takes me to posts tagged for that plugin e.g. https://wordpress.org/tags/buddypress and then if I click Add New, I find that the plugin tag is already added (and plugin name automatically appears in topic title too..except in case of bbpress and buddypress).
Because WordPress.org forums works like this for plugins, and because Buddypress is a WP plugin, I think that a more vibrant discussion at https://wordpress.org/tags/buddypress might even encourage more WordPress users to use BuddyPress. (more posts, frequent posts, fresh posts are usually, correctly or incorrectly, perceived as good support).
Add to this the fact that the forums on buddypress.org plain suck! They suck!
Don’t get me wrong here. People are fantastic and I’ve experienced volunteers jump to help out…and that’s brilliant.
But from the perspective of usability, Buddypress.org forums suck, probably because Buddypress forums suck…I don’t know for sure…I’ve been exploring and reading for weeks and haven’t yet installed Buddypress myself….but I did read in Buddypress website somewhere that Buddypress includes a watered-down forum…
Anyway, the point of this long winded post is that it surely would be nice to have a single place for support, that WP.org forums are a better candidate for such a single place, and that the team should consider merging the support…
Support is merged, yay!
So now, BuddyPress support is at https://buddypress.org/support and support for BuddyPress plugins is at https://wordpress.org/support
