When it comes down to to it, all we've got is based on belief, right? Reincarnation, viewed rather generically, is the vehicle for the route of one's 'soul mission' shall we say. One could be apathetic and say that the idea of living again frees us to be be lazy or cause havoc because we'll get more chances and impermanence, etc. However that is a waste. Make this life count so that next time you are perhaps in a better place with more opportunites. Plus it'll be good to have some enlightened storage to make the ideal of nirvana a little closer at hand

It's hard to swallow that perhaps the disabled etc have got some karmic overdraft but that's due to human sensibility, which ultimately is largely shed in the astral. Although, one could also say that they've just been dealt a bad hand, but that brings us to issues of destiny vs chance, etc. But of course, these people needn't be frowned upon or anything. Just if you oneday end up sick or something you will have to reach a point of acceptance, and finding meaning behind your circumstances is the main way to achieve that.