The way I remember it was that the 22mm tires where much better at the time than 24 or 26 mm tires. This was most because at the time most people didn't have belted tires yet. If you think about it under normal load and rotation, a narrower tire like 22mm would not expand to a very narrow contact patch like a wider tire would do(24 or 26). Therefore you had more contact patch.
The real reasons they died out was:
1. Introduction of belted tires
2. Roar outlawed anything less than 24mm
3. Much better rubber compounds came out.
I still use a set of 22 mm x patterns on my rally(tc3) when we run on pavement(a little sand). part of the rules state that the tires have to be treaded(some kind). The tires are awesome. The last time I drove it, I was 2 laps up on the rest of the field.