The mistake you're making there is the assumption that once you get the interview, you're on equal footing with everyone else. That is patently not true.
The common example that I like a lot is the staircase analogy. Essentially, everyone starts on different steps based on stats, ECs, ORM/URM status, location if it's a state or area dedicated school, etc. For the absolute stellar applicants, they're one step away from an acceptance in the interview. As long as they don't come off as a sociopath, they can have a terrible interview and still get in. For other applicants with holes in their application, they may be starting off on the bottom step. They can have a good or even great interview, but because of their starting position, they end up waitlisted or rejected.
A profile of 3.85/505 is a slightly above average GPA and a noticeably below average MCAT for MD schools. The fact that you had 4 interviews means that there were aspects of your application which caught the eyes of AdComs. However, the fact that none of them converted into an acceptance (assuming reasonable interviewing skills as you were able to net a DO acceptance) means that something in your app held you back from acceptance (most likely your MCAT, assuming standard ECs).
Your profile is perfectly in line with a typical DO matriculant, but it is also subpar for MD schools. Turning down a DO acceptance and more or less killing any chance you would have of getting another acceptance from DO schools to roll the dice in the MD system where you are significantly disadvantaged is a stupid gamble to take.