You have to remember that the player can choose what race he wants to be. the races balance out in that their stat maximums cap differently, so each race is geared toward a different job.
This is not to say that you can't make any race into whatever you want it to be, only that certain races do certain jobs better.
For example, if someone wants to be a really good Face or Shaman, they might pick Elf since those jobs are Charisma based.
If someone just wants to run into the middle of the fray and either beat the living piss out of things with his fists then you'd probably pick a troll.
I personally have made 2 human street samurai and 1 troll cyberer, and I prefer the humans. (the troll has a lot more physical damage boxes but will end up being a lot harder to advance due to loss of essence in cyberware.)
It should never bother you as a GM that players choose things you don't like or understand, it's about giving the players a good game. What you can do is enforce players in ROLE PLAYING their race. they should not be choosing a race just for stats, there's a whole mentality within each metatype. ~how trolls view human, how elves view trolls, how humans feel about any given metatype-even other humans.~
Each character must have his own personality, not just shooting stats, otherwise you're just playing futuristic DnD.