I only scanned the paper, but I get the impression the title was chosen specifically to grab attention. "An empirical study comparing the use of C++ lambdas versus C++ STL iterators and programmer experience" wouldn't get eyes on their presentation, and eventually, being posted to HN...well, it would, but they'll surely get more reads/downloads this way.
Clickbaiting for conference proceedings, who would have known.
Lambdas really are great.
Nested and member function local classes are actually implicitly friends of the containing class. Not all compilers were conforming in this area though.