You getting flashbacks to when Taylor and Danny confronted Sophia and Emma and the Winslow principal? When she asked to be transferred to Arcadia in lieu of any punishments and also didn’t want them to get expelled because they would only have Arcadia left? I wouldn’t be surprised if the capes needing access to the roof is exactly why it’s got more of a lock on it. The heroes get keys, along with the certainty that no-one will have snuck up there when the heroes get back.
Yeah, I don’t doubt that Arcadia was a good school – certainly better than Winslow – I just don’t think it was quite as perfect as Taylor’s narration indicated she thought. That’s just very rarely how things work in this ‘verse. Which is why I think Taylor has bought into the PR a bit too much and overromanticized Arcadia in her head due to her desire to go there and get away from the Harpies.
(There’s also Immaculata, but since that’s a rich kids’ school, I don’t think it’d be the main subject of Taylor’s daydreams, so she probably hasn’t romanticized that quite as much.)