There are a myriad of points which make this metaphor a insufficient argument at best (at worst intentionally obfuscating the nature of digital publishing and digital marketplaces as having similar physical analogues) in favor of the current app store landscape:
1. AFAIK anyone can manufacture and distribute CDs
2. The argument that anything below the cost to manu CDs is acceptable only holds water if you have an inefficient market that doesn’t reflect the actual cost of digital distribution.