The thing is, why wasn't the rule used before the Spurs used it? Nobody said anything about changing the rule when Don Nelson used it, or Phil Jackson used it, so why change it when Popovich used it?
And no, making a bad FT shooter shoot FTs is the same as forcing a bad shooter to shoot. Nobody said anything when Phil Jackson collapsed the lane and forced Tony Parker to shoot in 04. He clanged the shots, wasn't that as ugly as seeing Shaq missing his FTs?
The difference is that Parker worked on his shot to the point where he is at least respectable instead of whining about it. Learn from that, Shaq.