Increase PvP XP on klingon side to at least tripple of what it is now(and before you say that I want just an easy ride to max level,I am already BG2 and I dont intend to level another klingon in the foreseeable future).This slow leveling(compared to federation) is probably the biggest reason why you see so low amount of high level klingon players(the lack of pve content is not a big problem for me,I prefer PvP anyway).
I am not exagarrating when I say that leveling a Klingon takes at least 3 times longer than leveling a fed to max level(exploration missions are just terrible,I cant force myself to do them outside the daily exp. missions on max level).I reached RA on my fed char in 2 weeks,klingon was close to 2 months of playing(and I didnt play less).Imo it is ridiculous too that the PvP daily quests(goodluck charm,this is a good day to die,turret killer etc.) give the same amount of skill points as on lt level(I got 70/quest on captain).
On low levels at least you can get into battles fast,but the captain level was a real torture.
For better or for worse, Season 2 will likely speed up Klingon leveling anyway. I leveled mine pretty early after finishing my Fed and so doing the limited story/PvE missions and loads of PvP was pretty easily. I would imagine that you are right presently as the Klink population won't grow if the grind is too tedious and boring.
I say for better or for worse though because the focus on PvP is part of what helped make some Klinks better than most Feds. The PvE content may help speed things up, but won't help create a smarter player. Of course, neither will bumping the PvP EXP rewards since that would equate to less experience overall. It's a tough call. But whatever, I'd just like to see more Klinks in the queues than there has been lately.