The Windows Phone marketplace is a semi curated environment. This is both a good and a bad thing.
It makes the app submission process fairly reliable and keeps the very buggy and inappropriate apps out.
It does, however, require a human element in the certification process that can be subject to inconsistency and error.
Sometimes apps pass certification which shouldn't have. This is separate from any quality judgement, I'm referring here to apps breaking the marketplace rules and certification requirements
Fortunately, there is a place to report such occurrence: Reporting a Concern about an App in the Marketplace
If you're interested in and concerned about the general quality of what's in the marketplace - presumably because you want to see high quality, predictable apps which bring value to the overall ecosystem then I'd like to encourage you to report any such apps that break the certification rules too.
!!! This is not a place for reporting "bad" apps, just ones that break certification rules !!!
This isn't a substitute for also reporting such issues to the creators/publishers of such apps and engaging with them also. So that they can address the issues and learn what they shouldn't be doing.