I usually prefer working with mature stacks that don't require me to constantly work with flavor of the month frameworks.
It's great to broaden your horizons and all, but that is something that needs to be done judiciously and deliberately if it is to actually be of any use.
Me too, but to get started on a non-trivial project in such a stack is, IMO, the tricky part. It would be nice if I could do everything in the stack(s) I already know, but that's not always possible (e.g. backend vs web vs mobile app vs desktop app).
It's great to broaden your horizons and all, but that is something that needs to be done judiciously and deliberately if it is to actually be of any use.