I used to have one do-it-all bike for my 21 mile, one-way commute. It was a Specialized Secteur Triple with Sora 8sp components.
I'd take the rack off for weekend rides, but that was becoming a PITA.

When I changed my commute, and started taking the commuter train between Dallas and Fort Worth, I decided to change bikes as well.
I stripped the Secteur and put the 8sp drivetrain on to a Windsor Tourist frame. Then I put a nice 10sp road setup on the Secteur.
Now the Tourist is the commuter bike, and the Secteur is the weekend fun bike.

Then there is the single speed....