Personally, I'm a student and I just can't afford that many fonts. And if I'm doing a paid project, once it's signed off and all I'll buy it, rest assured. But if I'm not making money off it I don't see why I can't have the fonts, play with them, etc.
In fact, having the fonts allow me to consider using them in a paid project, and thus being able to buy them. But if I can't even use it to make the proposal in the first place... it's a lost sale.
Just my two cents