I think hull points make tanks useful for longer as they can fire when glanced. Hull points just mean you can only get glanced/penetrated so many times before becoming a wreck.
Its fair that once you have the right fire power in the right place lighter tanks are in trouble. But AP 13 and 14 vehicles are still tough, with Landraiders and monoliths being as hard as ever with 4 hull points and 14 all round armour they are resiliant to most attacks (except melta. lance and heavy ordenance).
I have been finding that close combat is actually the best way to blow up vehicles.
Your toast has been burnt and no amount of scraping will get rid of the black bits.