I too have this problem
on my first experience with the app store I just about tried everything that interested me.
but quickly found a lot where not up to what they claimed to be such as Dvd players and Bluray players none of which actually do?
Frankly the store is very sloppy and has no control over what is available.
so in the end I found the apps I use and in most cases paid for.
Now I have a short memory coupled with the ability to screw my pc up from time to time so I end up reinstalling my apps, I have no way of knowing which apps are the rouge ones or which ones I actually paid for which is again a very sloppy experience.
after all you would not want your Granny to keep a business card from a firm that ripped her off in the past.
I think they should at least be a way of tagging the apps accordingly. not just being told by MS to leave this compliant via the rating which can only be done by leaving a star ???
and before the robot says its by "design" if I where MS I would hesitate on admitting that