[shadowofneptune]

There are some forms of control flow which are difficult or impossible to represent in an iterative manner. The big example is VMs, where tail calls or goto provide noticable performance improvements over a large switch statement in a loop. Compilers have trouble optimizing such a large function, just as people have more issues maintaining one.

For what it's worth, syntactic tail calls seem to be the way to go when adding this to imperative languages, as it gives more control over stack usage. The WebAssembly VM has a proposal for a 'return_call' instruction, and rust has a reserved 'becomes' keyword.