KTM BIKE SERVICE AND SUPPORT

My son-in-law has an old but running KTM370 motorcycle. It needs repairs. A freelance crowd made a mess, and I suggested he take it to the dealership. They told him they don't work ( on THEIR OWN BRAND!) of motorbikes which are more than ten years old. Is this a motorcycle industry norm, or is it better to get a different brand. KTM franchise?