Tau don't believe in "letting the dogs in the house."
Kroot don't ride in transports at all.
Tau do not consider Kroot equals.
Kroot are a sub race which help the Tau in exchange for certain civil liberties, peace and what not.
Kroot come from a neighboring rock to the home Tau planet. They are more anamalistic and predatory where the Tau are more sophisticated and shun fistacuffs and melee warefare.
Kroot eat their dead and mutate rapidly as their system digests and incorporates their prey's DNA into their own. The Master Shaper controls what the Kroot in his formation eat and serves as a DNA 'shaping' foremen. If he wants them to fly, they eat lots of birds. If he wants them tougher, they eat lots of orcs... etc.
The Tau despise that. They tolerate the Kroot way of life as the Kroot have a role in the Tau's pursuit for Greater Good.
The more kroot that run off into combat, the less Tau that have to enter h-t-h combat. That's Gooder'er for the Tau.
Tau don't believe in letting the stinky predators share housing, mingle with the she-tau, or cruize in their spiffy rides. Well, in established 40K core design fluff anyway.
Who's to say what 40K "Tau Empires" will bring... (next Codex due in March/April for those not quite up on the Tau core development)
...and for that matter, who's to say we can't re-invent the wheel. Afterall, the AX-1-0 is outfitted wth non standard weapory, is a bomber instead of fighter-bomber, already has weak armor - and its proposed to get weaker armor and more neutered weapons while the points go up.
Then there's that issue of the broadsides being LV's too... and single LV broadsides taking up as much space on an orca as a unit of crisis now... and heavy drones somehow being an upgrade of regular drones... and stealths visibile at all ranges... and the lack of sms on the devilfish in E:A...
Cheers,
