It's really simple. It's a matter of skill. I had a Sorcerer as my main in the mid 30s, and today I rolled a Republic class. I was sick of 10+ minute queues and 98% of the time getting Huttball.
I'm level 12... my first 2 warzones, and the only ones I've done thus far, resulted in me being on top of the damage charts. One was a loss, the other was a win... but in both cases, I did just fine.
Sure, I felt naked without Sprint and Force Speed, among other things. I didn't have as many tricks in my bag. But still, I was able to get in there, do a lot of damage, and generally contribute to the team.
Want proof? Here:
Seriously... there's proof... you can dominate in PvP when you're the lowest level. Stop complaining and L2P. These forums are full of people whining about being outleveled and outgeared, and thus having a disadvantage. The thing is, Bioware compensated for that with the bolster system. The system works just fine. If you're getting your butt kicked... it's not the game... it's you.
As stated... there's evidence. Care to deny what's right in front of your face? I welcome the debate.