That's because a bunch of people who have houses in nice school districts, drive nice cars, have plenty of PTO, can afford a maid/babysitter, etc, etc, would rather redefine bourgeoisie than acknowledge that they're part of the bourgeoisie per the standard definition. Current social trends toward redefining words on a whim for rhetorical and ideological convenience certainly exacerbate the issue.

But that in and of itself is not even being bourgeois, it's middle class in the standard definition.

American definitions of "class" are just a way to obscure the lines between the owners and the workers. Most middle class people are petite bourgeoisie or labor aristocracy proletariat