There was an attempt to stop me taking it into work which failed. OH has been stopped from taking his non Brompton folder on a bus.
For me the problem is not about not being allowed, but those occasions where I don't want to drag it around with me all day such as - shopping (clothes as opposed to grocery) having to drag it in and out of different stores is a pain, and at conference type events where you might be popping in and out of different seminars and workshops.
I've just started a part time MSc, on the days I go to Uni we're in one classroom, but what do I do at breaks/lunch? drag it with me? Leave it unlocked in the classroom?
Also, dragging it any distance folded on anything but perfectly flat surfaces is a pain.
Totally agrre on the awkwardness moving it distances folded, even on train platforms etc, I wheel it unfolded and only fold it at the train door, same getting off, unfold as early as possible and walk it along to the outside.
I'm sure if you had a word with janitor, security or lecturer at colege, a quiet corner of a manned office or a locked space would be found, I'm the same at work with mine, it never lives in the (prior burgled) bike racks, theres plenty of nooks or crannies when you go rooting about or know people who have been. I have brought it in with me when I've been visiting other buildings and such, even into court when attending as a witness leaving it in the police office.
Non heavy rail Public transport has always had a bad attitiide to pretty much anything but a brompton (big reason I got mine was to ensure I wouldn't have problems on Manchester Metrolink)
Otherwise pragmatism.
It is my favourite bike to use and ride but nobody puts a gun to my head to do so & I accept there will be times, like you suggest, where it is impractical or undesirable to take it around with me folded or not.
I use public transport/car then or I'm lucky in central Manchester, that I have the excellent Popup Bikes to use. I'm sure many big towns now have independently owned and run bike park places as well as the grand gesture council hubs that our mandarins seem keener to spend the cycling budget on than proper routes to get there.
I wondered recently on a daytrip sightseeing stopover in London when checking our holiday bags into left luggage, if they'd store it for me as luggage if I chose to bring it on a work trip etc.