Gday Swoffa,
I thought the same thing when I was told, I have it on a 7ft squidgy spin with a Symetre reel and those that were at the Fig Tree social would have seen that I was casting every bit as far as them without putting in too much effort and I am about as tall as the 7 Dwarf's so I dont think it has effected the casting ability.
I guess also it depends on what you are using it for.
How far do you cast when chasing bream from your boat? Most of the time you are flicking not really casting.
I am no expert but I took the advice of a pro 'Barra' and it worked.
Not trying to stir you up and its interesting to hear opinions on matters like this one but I'll stick to my guns its worked for me.
I guess everyone has too try the ideas of others and come up with the solution they agree with.