I think this is a great idea & I'm sure if employers were willing to integrate or adapt their pension schemes to include BTC then it's a definite possibility that people would be willing to use it.
Most pension schemes with banks or brokers make you invest a fixed amount of fiat that comes out of your wages every month over a number of years (say 30-40).
Why do we need employers to sort our pensions out? We can do that ourselves and I think it's better to save money yourself rather than rely on state pensions or employer ones. Bitcoin allows us to become our own banks and that's what's great about it.