I have no doubt that Bevell is a fine man, but this is a good and necessary move.
Consider how often we joked about not having to tune into a game until the second half because the offense wouldn't get off the ground until the 3rd quarter. The offense was so unreliable that you could rely on it. Zero continuity from year to year, the constant reliance on the defense to save them--which was clearly causing tensions in the locker room. And of course the three years it took to properly utilize Jimmy Graham, who was a known commodity coming over from New Orleans.
If you need anymore evidence, just look at his production without Marshawn Lynch. It's easy to look like a good coordinator when your RB rushes for 1200+ yards four years in a row. Much of it after contact. Both Lynch and Wilson made names for themselves under Bevell for making magic out of broken plays. In my view, that's Bevell's legacy here, broken plays.
And even despite all of that, even if you still think he's a good coordinator and blame the personnel or whatever, the bottom line is this: he's the captain of the offense. The buck stops with him. Fair or not, the captain goes down with the ship.
