I think only two of the past goalies (not including last year) were NHLers when they left Calgary:
1) Karri Ramo. However what happened with him was an injury that he doesn't seem to have made a full comeback from. The Ramo we were getting before his injury however was a more-than-reliable goalie. Calgary did make a mistake in waiving him though, as he wasn't the reason he hadn't won a game at that point in the season - Hamilton's adjustment curve and Brodie's injury had way more to do with that.
2) Joni Ortio. When he got a chance he showed he was a competent NHL backup. He also showed puck skills and passed the eye test on rebound control. I think what happened was teams maybe offered him a two-way contract and he felt more comfortable making dollars in Sweden than risk being back in the AHL. If he were a North American goalie he probably would have taken a two-way. Maybe at age 24 he wasn't as good as Johnson at 30, but I think he showed enough then and enough upside that his time in Calgary probably cost him an NHL spot that he might have gotten developing for a team without Canadian Market Impatience.
Personally, I never had any faith in the likes of Reto Berra or Nicklas Backstrom, and we all know how the Jonas Hiller dealy went down.
As for last year, our top four defensemen played well (yes, even Wideman often had stretches where his play was underrated) enough that the goalies only have a mirror to explain their SV%. Ironically Johnson played his best hockey when the team played its worst, but that doesn't mean he didn't play his worst hockey when the skaters were playing well. Elliott I think started off mostly a victim of a disjointed penalty kill with the new coach, and really started playing well as soon as we turned the PK around. I didn't even think he was bad in game 1 against the Ducks, we got robbed by the refs. Game 2, he let in some goals he would like back but he gave us a chance to win. Game 3 was on 90% on him (10% on the refs). Game 4 he played bad and the team played not-good-enough too, I think benching Stajan was a mistake. Regardless, a ~.910 is a pretty good description of the overall level of play we got from Elliott - hardly a career-ending season. May never get a chance again in the playoffs though.
I don't think we're a goalie graveyard. However I also don't think we handled Ortio right, and we probably won't handle Rittich/Gillies/Parsons right going forward. There seems to be a threshold between development and opportunity that they cant' seem to figure out.