It seems to focus on the happiness of its star being determined purely by weight loss and sex without providing any help to address the sexual abuse David Smith endured as a kid. That abuse might have played a role in his obesity, and it may be partially responsible for the social skills he lacks.
Apparently he planned to light himself on fire before losing hundreds of pounds; suicide might still be an option for him as he realizes dating remains incredibly difficult, like his weight loss makes no difference in that respect.
It just looks like he is dating primarily to seek approval and continue building up a certain amount of self-esteem that a successful relationship would require.
Answer on Do you think the show 650 lb. Virgin is irresponsible?
Agree. Even though I've never seen the show, from the title and from what you describe it sounds that a show like that can never be responsible.