Originally Posted by
craftygeek
...No idea what the crutch reference is about...
It's a bit of elitist sniping/ribbing. Today you can have either friction(where the shifter can transition smoothly through its range of motion) or index shifting, where there are distinct "stops" corresponding to each gear when you move the shifter though its range of motion. With friction, the rider has to develop a feel for how much to move the lever, and when the bike is running cleanly.
In the early days of multi-geared bikes, friction was all there was. Then the first generations of indexing tended to be fairly crude, so performance sensitive riders still used friction.
Eventually this morphed into the opinion that a "real" rider did just fine w/o the indexing, and that indexing was only a help for those unable/not committed enough to learn to use friction shifters.
To me it's pretty much a non-issue. I have no problems with friction, particularly not in an open road setting. But I sure prefer indexing for city/MTB riding. There's less attention used up by the shifting when riding indexed. Now whether that attention is critical or not is another issue.
The strong point of friction is that as long as you have the right chain width and cage length you can pretty much mix parts any which way, which isn't quite the case for indexed.