They bend the truth because they can get away with it. Also, it’s not that hard and not unknown for a doctor to get paid to endorse a product or run a study where he can tweak things like timing to show a desired marketable result.
The pulse, joules, etc required to heat up the follicle enough to actually cause permanent damage to the follicle is known. And these conditions won’t be available in home use products because they’re not safe for home use. Think about it this way - if these home machines providedt the same results, why wouldn’t all professional clinics be using them instead of the $50K+ machines?