I can only think this has to do with cities' policies toward these things. Minneapolis has (supposedly) deprioritized driving lanes, so taking from car space is more palatable (not to mention that urban residents are far more likely to walk and take transit than suburbanites.)As others mentioned, the threshold for departing from grade seems to be less in the suburbs than in the city, which is backwards.
Robbinsdale seems to know how its voters get downtown, and it's not by transit. If suburban drivers feel even a minor rise in driving times (whether real or not) after a train took right-of-way (whether it took driving space or not,) there will be hell to pay.
The Met Council, before anything else, is a coordinator, not a transit agency. They're geared toward finding the political path of least resistance, not developing transit.