You ask is a long cast important, why or why not?
OK, My answer is both
1. Why? Because there are places on the beaches where you need to get out to the dropoff where the fish are most times, there are bars you have to get a cast out over to reach fish that if you can't reach them, it's the difference in catching or not. I hate having to catch a fish so far out that it gives those sea hoovers aka seals, a chance to sense the fish in distress and they chase it down as easy prey

, it sucks feeding those dirty animals but that's life. There are also spots in the canal like the others have said, you need a long cast, and yes it is much better to have the ability than not, that is why I rely on spinning so I can huck it out there and not worry about a backlash.
2. Why not? Because many time the fish are right in the first wave feeding as the bait gets disoriented in the curls. Or the rip in in close at the canal where the bass line up waiting for an easy meal. Therfore a long cast is not important.
that's my opinion.