The tweet is vague but I'll bite.
Don't let the fact he spurned us and bolted cloud your objectivity.
Young had 47-563-5 with TVD and an inferior OL. This is likely a better WR crew so he might have less opportunities but apart from CJ Daniels, we have WRs with thinner frames. We'll need some big bodied WR to pick up the crucial, contested hitch or slant on 3rd and shorts. Ideally, Daniels is the guy but what if he gets injured? Then all you have is Josh Moore. I hope Moore is the next Calvin Johnson but all we've seen of him is playing in shells with no defenders. If you can pick up Young cheap, you do it (but emphasis on cheap with his baggage).