You "caught" an Eskimos practice once & watched anywhere from 5 minutes to maybe two hours on the field. You based what you consider is his work ethic just on that. One practice for however long you were there. You never sat in on the defensive meetings. You never saw Stubler break down film. You never saw him conduct a defensive meeting with all of his players in the meeting rooms. You never saw the meetings he conducted with his defensive assistants focusing on getting ready for the next opponent. You never saw the discussions he had with the Esks head coach at the time. You never saw the preparation that he may have done in the Eskimo offices. You don't know what was happening behind the scenes nor do you know what the defense was focusing on during practice that day. But simply based on your observations of one practice his potential hire scares you? We could hire Wally Buono & there'd be fans bitching about that, too. No matter what O'Shea does, someone will always be there to say whatever he does is a mistake.
Here's what I think. This is O'Shea's first gig as a head coach. He can't afford to make a mistake & screw up hiring his coaches, especially at the coordinator positions. O'Shea trusts Stubler. He already knows the kind of coach that he is. Also, being an assistant coach in the CFL with the Argos he'd know thru the coaches grapevine if Stubler has become lazy & was just mailing it in with the Lions because he's 64. If O'Shea thinks Rich Stubler is the answer than have a little faith that he knows what he's doing hiring the guy. Stubler has proven he can run a great defense. I think having him here will be a great hire by Mike O'Shea.
No offense, but we (you included) all do the same thing here every day. We use limited knowledge to form grand opinions about something we know nothing about. You despised Joe Mack and are worried about Kyle Walters in the same way, but you've never spent any time with them either. No different.