As both a Notre Dame fan and a Detroit Lions fan, I'm a little partial to former ND players playing for the Lions.
That being said, both Golden Tate and Theo Riddick are better off playing for someone else. The Lions have had no direction for many, many years now. Every year or two it is:
1. Start Over
2. Change the Offense
3. Release/Fail to Resign Their Best Players
4. Trade Their Top Players
5. Have Players Leave the League Early Rather than Play for the Lions (Barry Sanders, Calvin Johnson)
6. Etc., etc.
Matt Patricia comes in and the Lions take several steps backward. Like so many failed coaches in the past, Patricia will be gone in another two or three years, and the next rebuild will begin. After all the Lions had Matt Millen as their GM for several years. That says it all.
As much as I enjoyed watching Golden Tate and Theo Riddick, they are both better off somewhere else.