if there werent any spazzes in bjj class, how would u be able to defend yourself against someone untrained in a street fight???...no one is going half assed in a street fight, and if u are untrained and on the ground in a street fight, u are going to be spazzing...so without some new white belts spazzing out and what not, how would u actually try to use it in the street...people arent just going to lay in your guard on the street, they are going to try to use their strength to mucsle you and they will be very spazzy...so really, if anything, sparring with "spazzes" improves your overall game in my opinion because its a similar situation to a street fight (well if u are looking for self defense and not to do well in tournaments)