If you have an operating environment where people stay suited up all the time like Heinlein envisioned, it may work. But I agree that a pressurized cabin is very nice to have, even if it adds some mass.
Most people working in space may still have to drag their own personal suit around with them as they transfer from vessel to vessel, though, even if they only wear it occasionally. I think it is analogous to having your own SCUBA gear, which if you've ever seen how people treat rental gear seems like a wise investment.