I think this would be pretty cool for a bit of added role play.
So I'm sure many of us have built support vehicles for the KSC, plane taxi's, crew transport vehicles even launch towers and such, but there not really useful.
Now if we where able to, say, drive up to the astronaut complex and then have the ability to select Kerbals to load on/off said vehicle then drive them around the KSC say to a plane on the runway/rocket on launchpad to load them up, I think that we could see some really cool functional support items, like a scalable launch tower that takes Kerbals to the pod door, or airstairs for example.
Obviously we could still play as normal and completely ignore the feature if we so choose, I just think It could add some more useful role-play options for those who want it.
Just an idea, feel free to shoot me down if its not tenable I know very little about coding and such.
There's probably some sort of Mod that does something similar, alas i'm on ps4.