I doubt invasions every hour would be a thing, and this has nothing to do with being lazy. An invasion would, obviously, require clearing out. Add to that the fact that invasions are meant to be a significant affair, with kaijus and large numbers of Tsi-hu assaulting the base. Those would hardly be cleared easily.
If invasions are to invoke a sense of tension and trepidation, they should be significantly hard. This means time required to clear the invasion while feeling that there is a challenge in the process, and then taking time to recoup from said invasion.
Too many invasions in too short a time period would tire out the community and ruin the charm of said event overall. While the statement says 'bases are invaded constantly', I doubt they literally mean 'constantly'. The game would then become a base defence simulator and leave little time for socializing or engaging in other activities.
I would be perfectly fine with massive-scale invasions twice or thrice a day, the others being limited to smaller events, akin to the incursions or the base capture events, scattered through the day. Variety is an absolute necessity, or players get burned out far too quickly.