Aside from the DCC aspects, which everyone seems to want to focus on, the fragility of the core-less motor when overloaded, even running DC, is an aspect that is not often considered. Indeed, the can motor itself is a culprit, because it is poor at dissipating heat compared to the older open frame motor that are now 'so yesterday'.
A pity really, because the modern can motor is simply an open frame motor that someone put in a tin can. They are, conventional or core-less, no better in any respect except for their ability to keep dirt and stuff out. And is some respects, a step backward in terms of ability to dissipate heat or clean the commutator or replace the brushes.