i agree, and its also in unreal tournament, wolfenstein enemy territory, half-life, call of duty, battlefield 2, and many other games that arent even based on the q3 engine. heck, ive even heard that halo has it to an extent (i dont play halo so i dont know this for a fact).
strafe jumping is in the game because it adds another element of skill required to play competitively. the way i see it, you either learn it or you die, just like any other game. in fact the defrag mod relies on strafe jumping/rocket jumping/plasma climbing for its very existance.
oh and btw, you dont need to have 333fps to strafe jump easily and effectively, 125, 76 and 43 work just as well. all that matters is that the quake 3 engine gives you a steady framerate at the cap you choose and the cap you choose is favorable for the greatest jumping distance. see this url for details if you wanna get technical about it:
http://ucguides.savagehelp.com/Quake3/FAQFPSJumps.html