While we all know now that the reason for "Shades of Grey" being a "clip episode" was due to the 1988 writers strike and the production running out of money at the end of the 2nd season, I still can't excuse it on that basis.
There should have been ways to tell this same story without delving into the scene vault every 2 minutes. The entire amount of time devoted to new scenes (largely, those with Diana Muldaur, Marina Sirtis and Jonathan Frakes on the sickbay set) is about 15 minutes. The rest is all clips from previous episodes. Surely the director could have found a away to squeeze out of the budget a few extra "new scenes" that would have been "Riker specific" flashbacks. Perhaps they could have used alternate takes or different camera angles of those same previous scenes (I'm sure at least some existed), or possibly even re-filmed some of the same scenes with the actors.
Frankly, I just see this episode (when it was first broadcast and still today) as a complete mess, a real cop-out, and a very depressing way to have ended the 2nd season..