The 70-74 bracket is very populated.
Queues aren't that long for battlegrounds.
If you stick at 70th, you can arena too.

I've got horde shockadins who will eventually reach 72nd.
The only reason to ever arena (at least for me), is because it is the easiest way to get the best pvp gear.
But with best in slot, aside from some zero resilience Sunwell pieces here and there, in a weekend of battlegrounds... there is really zero reason to arena, unless you like arena because there are no rewards from it.