I am much happier playing rhythm than lead, simply because I spend much more time working out chord movements and substitutions than I do thinking aobut how to phrase melody lines. A good lead player is indispensible for a good sounding guitar band, but I must say I reckon that a good rhythm player is even more essential. One of the things I like so much about about Hendrix is his skill playing rhythm, rather than for his "lead" work. He demonstrated that even in rock music playing little fills of one or two note flurries can sound much better than simply strumming a six string chord for two bars. If no-one wants to play rhythm then it's because they're either really dedicated lead players who would be wasting their particular talents, or, more likely, they are not good enough guitarists, in my opinion.