I have no problem believing it, and I still have no plans to ever breed pin x pin (or spider x spider, any other "probably/maybe dom x probably/maybe dom"), at least not for a long long while.
The way I look at it, in the ball world, each gene that an animal carries makes it more valuable and probably cost you more money (at least, that's still the way things are at the moment). If I breed, say, a lemonblast to a pinstripe, the best I can hope to produce are lemonblasts (granted, yes, it's a theoretical 25% more pinstripe gene animals -- but we all know how odds go). I'll have to market the blasts and pins as "33% chance possible homozygous," or, as has already been stated a few times, breed them a whooooole bunch in order to demonstrate homozygosity.
If I breed a bumblebee (same price as a blast) to my pinstripe, I have a shot at spinner blasts ... Those are really neat.
I guess you could try putting aside a few groups of pinstripes to try and get a bloodline of homozygous pins going -- that might be kinda cool -- but it seems kinda more like a "gee whiz" sorta thing to me than much of a viable investment ...