But seriously, every under-used feature harbors a ton of bugs in the compiler and drains resources for implementation. Promises, for example, seem like a "feature" in R that only really serves to destroy performance and no one uses it.
Agreed, but it's hard to know in advance what features will be useful, and once a language is established, it's hard to remove less-used features without breaking existing code.
;)
But seriously, every under-used feature harbors a ton of bugs in the compiler and drains resources for implementation. Promises, for example, seem like a "feature" in R that only really serves to destroy performance and no one uses it.