Most 'scopes these days (including this one) run a variant of Linux so they take time to boot. They have file systems, USB drivers, etc., that probably shouldn't be reinvented from scratch (You want bugs? We've got bugs...!)
OTOH it could have a sleep mode. This is Android...
Maybe the FPGA, front end, etc., can't go to sleep so they'd have to leave most of it powered on, including the fan. I wouldn't want a noisy 20W device constantly running on my desk.