If these guys on the sidelines are so good why are they not getting on the field when there's been a fairly obvious need? We've been hearing that for how many years now that the guys on the sideline are SO good, but yet here we are years later and I'd argue the top position of need is still WR (though I'm sure a handful will say QB).
Also, who's to say that Jay Johnson didn't have this transition in the back of his mind the whole time? People assume he was recruited with the sole intention of being a QB, but Johnson may have approached it as give a kid the chance to earn time there, if he doesn't, we'll move him to WR. I don't get why people get so hung up on position changes, like that means the coach failed. Hell, for all any of us know Johnson was never convinced he'd play QB, told him he'd get a chance but had it in his mind to move him to WR from day 1 (can't think of the player that Kill signed because he'd "give him a chance at QB" then converted him a few months in, but same thing).
Finally, the argument that earlier in the year Williams was ahead of Green is really meaningless. From all reports, Green has been improving by leaps and bounds. It might be a situation where the coaches are convinced Green is the guy and convinced that Croft and/or QB(s) to be signed this year will be an adequate back up squad, so they want to put Williams in a position he can contribute.