Fly fishing for pike demands the use of robust fly rods to be able to cast the heavy pike fly lines required to present large flies. A 9 or 10 foot rod designed to cast a 10 weight fly line may also possess adequate backbone to restrain large fish. Pike landed and returned to water quickly, while using the least amount amount of fuss, will recover so much more quickly than fish that happen to be played to a standstill on light weight tackle.
This really is especially true in hot weather when oxygen levels are low, and in Trout waters where pike grow to specimen size a bit more quickly but tend to have a shorter life span because of their bulk. There is no place in modern fly fishing for line class fishing where praise was once given for landing specimen fish using the lightest line possible.
A Pike fly rod will be turning over potentially very large flies, possibly 10 or 12 inches long. Although modern pike flies tend to be made using synthetics like Semperfli Predator Hair which sheds water to minimise fly weight the pike rods still turns over larger weights with the fly line, leader and flies which is why the powerful rods are required.