They tanked last year so why did they fire Culley? The Astros tanked, why did they fire Bo Porter?
For the millionth time, the players and the coaches aren't the ones out there tanking. They're trying their best to win. It's just that with the way the roster is constructed, their best isn't nearly enough. The players and coaches aren't tanking, although the coaches can influence it if they have orders from above, but it's the guy above, the one putting the roster together, bringing the players he has in, who is tanking.
But as far as coaching goes and why people are down on it is because you can clearly see there isn't much coaching going on. There's no improvement from anybody. Mills wasn't that good to begin with but he has clearly regressed. Pierce was a bright spot, top 5-7 in rushing for most of the season, but as a team the Texans were still mid 20's in rushing. Hell, in 2 games after being called up from the practice squad, Freeman was the Texans 2nd leading rusher for the season. 2 games!! The defense is constantly running themselves out of position to make a play. Never mind that they can't tackle. And none of that has gotten any better the entire season.
If you're thinking they accomplished their tank job, why blame the coaching, just remember who put the coaching staff together as well. Yeah, that same guy who does the roster.