man, you really gotta know what racing is before you try and bash it.
racing isnt just turning around gates (well, it is, but theres way more). i can say from experiance, that there are some hard fucking courses out there. in any given course, you may encounter:
-knolls (nolls? sp? the bumps you can nose butter off/catch a bit of air) that you gotta seriously suck up to stay even close to the ground
-ruts- these things are a bitch- they are basically just gigantic divits where most of the people ski through (right in the line where you should be - that is if th epeople you ski against are any good haha)
-turns (obviously)
-massive steeps- there fucking steep, and when your going fast its not as easy as you think to stay up while trying to not catch air off a knoll, which is probably there to make the course ahrder (meaning, it will launch you if you dont hit it right) with ruts...
my point is- whipping it down at 50 or so mph (which is a reasonable speed for some courses (gs/super g), if not slow) with knolls, ruts, hard/sharp ass turns, all on the steepest trail on the mountain, is NOT easy. trust me, i raced for a long time and i can say this is true. it definatly helps me ski all mountain, and the two out of the 3 best freeskiers at my mountain raced growing up (one actually still races at his high school...).
if you dont belive me, watch the jon olsson video blog of his first race- watch his skis- to make GS skis (which are fucking stiff, belive me) shake that much you gotta be going over some serious shit.
heres the link to the JO video blog thing i mentioned:
http://www.jon-olsson.com/videoblog/
NOW, as to not be compleatly biased: kids who ski park definatly do have more controll on things like being in the air spinning and stuff off of park features. this may mean that they are better in CERTAIN aspects of the skiing all mtn (maybe dropping cliffs for example).
Also, growing up as a racer- me and my friends would DAILY chinese downhill (race down any trail basically fighting eachtoehr w/ poles and stuff- its good fun), cruise the park (with twins of course... well at least me hahaha) and ski all mtn.
and to all of the kids who think they can ski faster than most racers at their hill- well, you probably either took lessons as a kid and can ski pretty well, raced a shitty racer, didnt race anybody and are claiming that statement, or can beat them straightlining it down a hill (which i still doubt). Race them through any type of course- it is their domain and they will win, just like you will prolly be better then them in the park or whatever area of skiing you excel at.
basically- racers CAN ski all mountain better than the average park rat (in my opinion of course)