Yes, there are definitely some lousy grad
players. That's why I didn't say that it just takes time
to make good players, I said time _and_ hard work
(and also spite, talent, other other lesser factors).
However, all that hard work does take time to pay off,
since there is a steep learning curve that takes at
least a year or two for even the best players to
overcome. There is also a plateau at some point, which
explains why the best undergrads can hold their own again
the best dinosaurs.
The correlation between
school size or reputation and team strength is pretty
tenuous. People not on the circuit usually assume that the
Ivy League schools always dominate the field, for
instance.
Huge schools have a theoretically larger amount of
people to draw from, but in reality, the number of
people on any campus who are interested in playing quiz
bowl is pretty constant, no matter where you go. The
same thing can be seen on the high school circuit, if
you are unfortunate enough to be involved with high
school competition.