It's not "true Generics" it's a different generics tradeoff (tradeoff not just for backwards compatibility sake).
And LINQ is not that important in the grand scheme of things. Are Haskell, CL, or Smalltak also "far behind" C# for not having LINQ? It's just another feature. You can most of the same things with a fluent interface, streams, and functional composition, and without straying off the regular syntax of the language into a LINQ DSL.
Besides, last time I've checked, Java still has the performance edge over C#.