Ironically this subject has stayed on the back of my mind. It's funny how that happens sometimes isn't it?
I do agree with you
@tony_gunter that Johnston was passive and didn't have any kind of bold idea to give his side a chance to turn the tables. If he wanted to concentrate elsewhere he didn't send orders to do it as his first order of business, specifically pointing a location. Part of that seems to me lack of time to reconnoiter but it can also be he didn't want to assume responsibility for the debacle he could foresee coming, as you point out. Even a bold instruction and plan wouldn't have probably worked out because of the communication problems I pointed to, but the fact he didn't try to do anything but get away is significant for showing timidity in his generalship. It's a fair criticism.
It's odd that Davis would go back to J.E. Johnston when he didn't trust him and would publicly undermine him with criticism. In normal circumstances one would think he'd need to be removed if the President's lack of confidence is that deep. Eventually Lincoln had to move on from McClellan even when the options that came after him proved to be worse for a while. He wouldn't have found a General who could get the job done if he got stuck with the same generals who proved unsatisfactory. Davis didn't try out enough other people. I know that seems easy for me to say. It's ultimately why all these discussions are theoretical.