It wasn't his DC abilities which stunk, it was his HC ability that stunk. He didn't have the right personality for being a head coach and had trouble controlling his temper, which we all knew. We also know that Bo was giving up responsibilities and getting mentoring on how to be a better HC, and part of that was delegating responsibilities which he did, including the DC responsibilities. He was actually doing all the things asked of him, and while it didn't work out, the fans kept demanding more and not until that sleaseball Eichorst was hired did we know this was going to end badly.
Also, If his DC abilities were so bad, then LSU would not have hired him back. Nobody is going to fire him in just 3 games, and he is probably rusty, but the guy did try his best outside his comfort zone, which is more than we can say for most people. I see no use in seeing people kick him here when the current coach isn't doing so hot either. It's a bad look and makes the fan base look like they are the ones on drugs. lol