My bike doesn't need it. It has a modern airbox system with a large, flat cleaner element, probably close to a sq. ft. in size. Opening it up even more (there are kits available for those who can't leave well enough alone) will produce a lot more intake noise and a small increase in power. Ditto the exhaust system. And it's unnecessary because I already have a power to weight ratio better than a VTX1800 with 15 extra HP from opening up the breather and exhaust.
But that's neither here nor there. My main point was that making a racket with extremely loud or open pipes doesn't increase performance noticeable, but it does piss a lot of people off. Moderately loud pipes and a judicious use of the loud handle may be OK if a lot of your riding is done is essentially unpopulated areas. Where I live even out in the country I'm passing several houses per mile, and I'm pretty sure they didn't move out there so they could listen to unmuffled bikes roar by.
Too often the same guys riding around on straight-pipe cruisers are the same guys who would complain about the racket from kids cruising through their neighbourhood in their Civics with fart-can exhausts and massive stereos pumping out bass you can hear from a block away. I lump them all in together - rice-boys, weekend outlaws with straight pipes, muscle cars with glass packs, whatever. It's all unwanted noise to me and others.
I guess I piss a lot of people off then. I'm glad that you like your motorcycle to be quiet, I don't, and that's that.