I believe in LQG where the theory itself regularises itself (quantised volumes).....string theory is supposed to account for infinities too cus the interaction is smeared over extended objects rather than point particles.... First of all interactions dont occur at points in perturbative quantum gravity in the same sense of Fermi theory. In string theory we take a step back in that strings do interact directly as in Fermi theory. Second, so what if it is extended objects that interct??...say an extended object interacts with another extended object say at n points - doesnt that just say the UV divergence will be a power of n times greater than that for point particle interactions just divided by n?? Probably a stupid question...Im bit tired. cats among pigeons.