Yes! I recently had a deplane delay. It went as smoothly as it possibly could — new plane already located and assigned, three gates down, everyone off, straight over, and back on. They delay posted fifteen minutes at a time, though. We left a tad over an hour late.

Sometimes the rolling 15 minute delay is warranted, when the fix is uncertain, and it's worse to post an unnecessarily large delay. But with a deplane, there's no way it will be less than an hour, so the OP complaint is totally valid.