Wow, that sucks. Hope you have better luck on your next trip, whether its on a KTM or KLR or whatever you choose.
FWIW, from a distance this seems like more of an incompetent dealer mechanic than anything particularly bad about the bike design. On a stalling FI bike with any decent amount of mileage, they really should have checked the fuel filter(s) to make sure they're flowing enough gas (assuming this really is the problem, finally).
2013 BMW R1200GS-LC
2008 Suzuki DRZ400