It's not that long ago that string theory was considered a crackpot idea. Now it's pretty much accepted as the basis of particle physics. People shouldn't be so keen to dismiss a hypothesis because the evidence for it isn't available YET. Who knows what future experiments will reveal as conundrums needing to be solved?
I'm not sure it's that clear. It is currently the best funded research but so far there is no proof. There are competing theories (loop quantum gravity primarily) that are just as likely to be proven.