I only ever fish rivers where the majority of the pike are less than 6lb, and because the river isn't the widest in the world i dont have to cast far, i use an 8wt and am happy doing so, so far i've caught three into double figures with the biggest being 16lbs, and although the fight was thrilling enough thank you very much! it was not overly long, and after being weighed and photograpghed the fish swam off very strongly.
I guess fishing big stillwaters where a lot more casting is involved a heavier rod would ease the arm, but on an intimate river it's a few casts then move etc. Each to their own, but the fishes wellfare is the most important thing here, not how much fun you can have
Cheers,
Graham