Huh? There are plenty of twist-handle joysticks that give you 3 analog axes. Some will even give you 5 or 7 (One or two mini-sticks)
The idea behind a controller like the one under discussion here is that its three axes are, first, all translational, and second, all in direct correspondence with the motion they impart to the spacecraft. With such a device, no mental mapping between control axes and motion is required. You just push the controller in the direction in which you want to add thrust.
If it's still unclear what that means, look at this diagram [1] of the Apollo translation controller. Disregard the limited rotational capability for which I have been unable to find documentation. Observe the translation axis diagram alongside the handle. Note the three degrees of freedom it depicts. Consider their correspondence with the three degrees of freedom in which a spacecraft may experience translational motion.
To provide a matching capability, the joysticks you're talking about would need to allow for pushing the handle into, or lifting it out of, the base. I doubt anyone makes a joystick like that, because it would not be a very useful capability to add, and the engineering requirements and effect on retail price would be significant.
Also of note: while I've never played Kerbal, years ago I was very seriously into Orbiter, which is a somewhat more rigorous simulation. Especially when maneuvering in close proximity to another vehicle, you actually wanted to avoid analog control of RCS thrust, because that's hard to control precisely and it's very easy to find small errors compounding and your ship getting away from you. So you'd put the RCS in what I want to say I remember being called "vernier" mode, where each control input regardless of magnitude or duration produces a specific, calibrated quantity of thrust, which can be precisely counteracted by the opposite control input. So at this point, you're effectively treating an analog control device as digital - which works, but something like the three-axis controller detailed here would actually be a lot more comfortable to use for vernier control. If I still played Orbiter at all, I'd be asking OP for more details on the parts he used and how he put them together, so I could build something similar for my own use.