Originally Posted by Kebab-Kastike

I'd like to point out that they aren't totally random - how much damage you have done on that session does have an effect on how many crits you can throw at enemies.

Snipped your example as it was incorrect.

The crit mechanic is a known quantity and is detailed quite well here:
http://tf2wiki.net/wiki/Crit

Short form: Everyone has a 2% crit chance on ranged weapons (outside special cases like the sniper rifle/huntsman). The amount of damage done in the past 20 seconds, capped at 800, may add an additional 10%.

Since everyone has an equal chance I think it is silly for "competitive" play to have no crit. That would be like the PGA mandating all golf courses be domed because the wind is variable from one second to the next or WCOP mandate every hand be dealt off a fresh pack of unshuffled cards because some people get bad runs of hands.

How one deals with variables is a part of competition and is pretty much the definition of a pro over an amateur.

EDIT:

As for servers I play on TheVille and SourceOP. SourceOP is my backup but far more popular than TV's servers. TV, however, is much better run and a higher class of criminal... er... player.