It's okay to move someone if their is conflict or turmoil, but you have to get max value for a superstar player like this. Aside from the poor return, the fact that this trade didn't leak and nobody saw it coming is a great indicator that all teams weren't in on this.
I mean, Johnson has been a backup caliber RB the past 2 seasons with injury concerns before that, and he turns 29 this year. Hopkins puts up Probowl numbers with scrubs like Mallett and Osweiler. Houston fans should be livid.