No, it isn't. Any decent datacenter will have on-site generation in event of power grid failure, anyway. When I was an intern, the company I worked for would routinely go off grid during the summer at a call from the electric company. The electric company actually gave us significant incentives to do so, because us running on our own 12MW generator was effectively like the grid operator farming out a 12MW peaker unit.
The power company has a long list of who has backup power. I know of one factory where the generator was installed in the 1920s on a boiler from the 1880's - it is horribly inefficient, but the power company still gives the owners incentive to keep it working because for 4x the normal cost of power and 12 hours notice that generator can run the entire town it is in, which they do every 5 years when things really go wrong with the grid.
What is your definition of regularly, and what qualifies as getting it fixed? I know lots of places that had things scheduled, but on the day of, something "came up" that the test was pushed. I've seen others where they tested by only firing up the generator, but didn't actually use it to power the facility. I've also seen repair tags that sat "unlooked" at for years.
Not every facility is managed/financed the same for such a blanket statement as yours.
Ok!