It's tempting to assume the former, but I seriously suspect the latter.
As a user I've seen this happen repeatedly. Search can't find an app even if I enter the name.
This happens for mundane but specialised apps - train timetables, toll payment apps, and other apps for which there is literally no alternative, never mind one that might somehow sell better and make more money.
I don't see how this possibly benefits Apple. Possibly there's some not very effective "optimisation" happening, but it's also possible search is just plain broken.