oliveDrab, all due respect, but that's like asking why guys put a .60 on a .40-size plane. Modelers have loved power since the invention of power. There are some jet guys who look down their noses on jets that have less than 1:1 thrust, and that's too bad. When I test flew the R54 over a decade ago with a RAM 500 putting out 11 pounds of thrust (when it started), it was breathtaking. Then I went to 14 pounds of thrust and it was even more eye-popping. I think any new turbine pilot would be pretty darn happy with a P60 on their R54. More experience pilots gravitate towards the higher-thrust choices and I'm just glad the R54 has pretty well proven itself to be up to the task.
One other point... think about what would happen if I recommended up to 22 lbs of thrust. I will leave it at that.