There are a handful of schools that I know off the bat that are 0+7 year MD programs (E.g. Baylor).
The largest difference (which Tinkerbell stated) is that those programs are insanely difficult to get in compared to the 0+6 pharmacy schools.
My only chief complaint is that there is a certain maturity level that is gained by completing 4 years of college (I'm not suggesting that all college grad's or even adults are 'mature') that isn't gained through simply coming out of high-school and jumping into a 0+6 program. I'll reiterate this again, even 2-4 years at a university makes you grow up (need better time management skills, ability to be somewhat organized, teaching the delay of gratification [like skipping the thursday binge drinking in order to study for the exam at 8am on friday]
)
Also, I just feel you get to sample more career choices while in college.
Heck, I went from Biochem/Pre-Pharm to Math major to Pre-Med to History major to Religions major back to Biochem major (finished it in 4 solid years + 2 summer schools). It reaffirmed that I enjoy research (hence my MS), then after grad. school I realized I would like to do more Bench-to-Bedside type of work (clinical/research/combo); hence I'm in pharm school now.