Family has been mentioned. Beyond that?
Okay, I already took a stab at it.
1. He took the job shortly after being canned. I'm sure he was excited to get the offer so quickly. Everyone wants to have a "home" especially after being rejected
2. I speculate that he had to make "concessions" to get the job. James wants/needs to keep that side of the staff happy. Terry, Dex etc. have a great deal of input. Also, I think he was expected to make his defense as "friendly" to Manny's schemes as possible. This was a no brainer with so much returning talent.
3. Sometimes you agree to things and then you have time to see how it actually works. My guess its family, and an opportunity for full autonomy in running the defense. I don't think he was going to get it here with Poindexter, Smith, Barnes and Conner on the staff.
ps As I stated in an earlier post. The negotiations have been going on for days. Either Franklin didn't want to keep Allen or he couldn't give him the situation he wanted.
There were 2 situations that raised my eyebrows on Thursday, where (LB) King was mismatched and PSU got burned. That shouldn't happen.