If the wire wheel works, and doesn’t destroy the surface that you’re trying to paint, then that could be fine. Hand scrapers are pretty safe because unless you get really careless and use the tool totally improperly, you’re just scraping flat against a flat surface. So all you’ll be removing is loose paint (and minuscule amounts of siding). Wire brushes can scratch pretty deeply, and powered wire wheels can eat right through siding in no time.
If you’re very careful (or maybe if you made a jig to ensure that the wire could not penetrate deeply – like the guard on a skilsaw, for example) then a powered wire wheel should work fine. You also don’t want to overheat the drill motor, because your use for “scraping the side of the house” would be a huge increase in duty cycle over the design intent.