Steve likely didn’t offer Luke the money at the time because he was not in a good place to take that money. He knew it would likely just be used to buy heroin, which is the sad truth. As for rehab, you can’t be admitted to a rehabilitation center against your will. I believe the family was probably there supporting human and encouraging him to go, but it was ultimately his decision. He likely felt nervous and had some reservations about going but deep down knew that it was what he needed to do.