It is not completely dead, occasionally you can catch a bg or two. However this may mostly be true on Alliance side. Between December and April, the Horde overwhelmingly dominated the bracet with constant premades and incredibly dedicated and active individual players - including healers (one hit 200k hk's a few weeks ago). To the extent of extinguishing not only the fun-factor, but the mere will to even log in for at least four of us on Alliance side. Perhaps even more. Not that they are to blame though (or anybody for that matter) - as one Horde twink-guild's officer said this was merely a not-even-fully-successful attempt to somehow counter what a primarily lvl 79 Alliance twink guild has been doing, in terms of similar, constant premades. As a solo joiner, you had a much higher chance to wind up in a typical one-sided roflstomp in that few month period than to have a decent game. Regardless of what side you were on, it wasn't fun: Either the enemy team stopped resurrecting...or you did. I'm not sure when or how it happened exactly, but it seems that at some point, things just got too bitter, and ever since, both sides are taking winning too seriously, limiting the fun of others, too.
Not sure what the current situation is at 70-79 (moved back to playing 80 stuff), but it doesn't sound like there was much improvement. Either way, as long as you're a mono-faction solo player, you may end up having a hard time. Try using mercenary mode, or have at least one character in both factions to reduce waiting time. Keep in mind though that you have chosen to start twinking during what seems to be difficult times for this bracet. Oh, and if you're thinking of getting a lot of HK's... you may want to stop levelling at 78. A very significant portion of premades consists of solely lvl 70 characters, and a lot of players tend to choose 70 over 79 anyways (I really think both are quite fun!). Losing some extra stats and an upgrade to a couple of your abilities to get a HK for a 70-kill may end up being a reasonable tradeoff. Good luck!