I agree and on flat bar bikes there's no excuse. When a set of Clarkes M1 with rotors and adapters retails for around £60 at OEM they must be peanuts, OK not the best but beat mechanical hands down.@benjabbi my point exactly, even if you get them working ok a couple of rides (if that) and they've gone off the boil! also they get worse as the get older.
i should also point out that i feel the same way about most of the cable brakes, not just the tektro/trp etc, i find shimano calipers just as sucky, the BB5 and BB7, i seemed to get a good set and a bad set, sometimes on the same bike!