While the classic BFG TA is a good looking tire, the fact of the matter is that they have not had any technological improvements made to them since the late 80s, early 90s. Combine that with BFGs pointed interest in producing 17"+ sizes over 15" and it is easy to see that their 15" tire line is a candidate for cost cutting material purchases and low cost manufacturing techniques. Is that the direct cause, probably not, but you add up enough factors and you have greater opportunities for defects. There are been much better 15" tires available from other manufacturers than BFG now days.
Personally, with what I've seen, Mickey Thomspon, Hoosier, and Goodyear are the only ones putting any development and tech in to 15" tires, and most of that effort is in the race tires, but it will have some trickle down impact on street tires.