It isn't a big deal to take the strings all off when you gotta. I don't think you should do it every time you change the strings - at least not as often as I change them. And cleaning a guitar every time you change the strings is kinda anal, too, isn't it?
It can take me months several adjustments to get the interface of the parts where they need to be for my guitars to play "sweetly". I don't think a setup is static - especially on a bolt-on neck guitar. I don't chance disrupting the delicate balance, so I change strings one at a time. every once in a while, I take them all off and do the 30,000 mile maintenance. I have had to adjust the trussrod after taking all the strings off at once before. I don't like to restart the long process of dialing in sweetness, so I'd prefer not to do stuff that can dislodge this collection of screwed-on pieces parts.
This is after 25 years of shitty bolt-neck guitars. I think the acheivement of a sweet setup is a religious experience and deserves respect and care.