Are there any advantages in using proprietary encryption? Proprietary software generally relies on the fact that in keeping the encryption algorithm private, it gets an extra layer of security implying "Security through Obscurity." Obviously this phrase has been hotly debated and surely is only acceptable if discovering the mechanics of a proprietary algorithm doesn't actually reduce it's security. 

Is there any other reason you would use a proprietary encryption since my research has proven there to be many more disadvantages than advantages!
Yes, there are advantages to the attacker.

Using a well vetted encryption algorithm provides a better assurance of security. There may be cryptographic algorithm flaws and/or coding mistakes.

As noted, relying on the algorithm being private just adds a layer of false security.