The type lambda syntax is arcane, but that's not a feature - indeed if anything it's the absence of a feature (would you favour explicit support for type lambdas, like the plugin does?). If you're complaining about the syntax of curried functions then again that's not a complaint about a feature; likewise _.
I'm not saying they aren't issues, but none of the things you mention is about Scala having "too many features".
It's not a language-level feature. It's a pattern that makes use of several features - type members, structural types, member selection. (You can often write these things more readably by splitting them onto two lines, putting the type alias in one place and the use of it in another, avoiding the need for the structural type and member selection). It's like the visitor pattern in a language that doesn't have pattern matching, or an explicit Y combinator in a language that doesn't have recursion.
Some newer languages have this kind of functionality (in Haskell it's a GHC extension, I think).
I'm not saying they aren't issues, but none of the things you mention is about Scala having "too many features".