Thanks for letting me know the reason behind this behaviour. Maybe as a compromise Ctrl+Shift+Mousewheel could zoom using locked increments, save me having to move my hand off the mouse. That would be ideal for me, but if not I guess I can use Ctrl +/- to do my zooming, it's not such a big deal.
By the way I think there might be a little bug with the mousewheel zoom. If I Ctrl+Mousewheel up one notch, it goes from 100% to 112%, then down goes back to 100%. If I do it again it now goes to 111%, and back down to 99%. It seems like there's a slight miscalculation on the before/after sizes? Do you think this is dependent on my mouse? (Dell M056U0A). Anyway since I'll be using Ctrl +/- from now on, I'll never see this bug again