until you can't get any closer than 30 feet. A big part of the enjoyment of fly fishing for most people is casting well. Much more so than spinning or baitcasting. A gifted caster can do well with any rod, as long as the line is matched to it. I'm only an OK caster, and I've found with "softer" action rods I have issues making good casts--- the issues are with me, not with the equipment. An exceptionally gifted caster can launch a tight loop a long ways without a rod at all!! Lefty Kreh said "EVERY rod casts better than the person using it."
That's why I said with MOST small rivers and streams, and I never said that it isn't good to be able to cast well,I was just pointing out that in most holes you aren't going to be able to put ont 90 feet of line before geting hung-up.