This is the part I don't get. Absence or presence of rules shouldn't matter should it? If your preference is free-form, then having rules, not having rules, either way, doesn't actually matter. If the rules are there, you ignore them. If there are no rules, you ignore that fact too. Either way, it's impossible to actually hinder freeform play.
But the reverse is certainly not true. The lack of structured play is a pretty significant impediment to a style which asks for structured play.
I can see an element of it, in that a presence of rules may lead to players anticipating that those rules will be used. An absence of rules means the only thing one can do is talk with the adjudicator, in this case, the DM. But that is the
players looking for something to support
them; the DM has exactly the desired amount of support, namely zero. In this case, the absence of rules provides an indirect benefit, removing another impediment, player expectations. But the removal of negative things is not the same as providing positive things. It cannot be.
The analogy that comes to mind is people in a workshop. Rules are like subordinates, journeymen or apprentices or the like, who assist the master craftsman with various tasks. But sometimes, what the master wants is to do everything
herself. To have no inexperienced hands, no untrained eyes, disturbing the creative process. To be free of distractions, to have all tools working only and exactly as she desires. In which case, the shop will be cleared of all assistants--all
supporters--so that she can work her magic alone. The journeymen and apprentices dismissed so are, necessarily,
not supporting her--but they are
permitting her to work alone. She is not getting help from anyone else--which is what "support" means. She is simply not having to deal with any of the negatives that come from having other people in the shop with her. (But, in so doing, taking on all of the negatives of working alone.)
And that highlights the flaw of the "lack of a vehicle supports better health" analogy. No, it does not
support anything; however, in lacking a vehicle, if one wishes to continue getting around, one must depend on one's own body for locomotion. This may
permit the person to get better health, but it may also seriously harm them. (Believe me, I am
intimately acquainted with how much a person's health can depend on having regular transportation.)