Exchange Rate Widget

I have just purchased the Exchange Rate Widget and to my dismay found it does not work - all of the conversions are incorrect. After 20 minutes of fiddling around with preferences it still spits out incorrect values. A further search on the net revealed several reviews of the product - all of which were critical of the apps poor performance

My Question is why do Apple continue to publish ( and accept payments for ) software that is so inferior? and why

don't they take some notice of bad reviews and remove the product so others don't get caught?