The Street models are HD's way of trying to catch 'em young and build some brand loyalty. They're cheap(er) than Twin Cams and made for the shorter rides the in-city millennials do.
At 2014 Sturgis I test rode the Indian Scout and compared it to the Street 750. Not a direct comparo, since the Scout is several $thou more, but disregarding the $ and engine difference (69 ci Indian, 46 ci HD), several things are obvious just when looked at in the showroom: The Scout is top-notch in fit, finish, and design, and comes in 4 colors for the same price. The Street wants $300 extra for color paint, wiring harness at the neck is fugly, and the horn looks like someone forgot to include one on the original design, so they just threw it on at the last minute. Looks like cr@p.
My point is that HD isn't going to win any brand loyalty with poor quality, nickel-and-dime philosophy, and poor service after the sale. A legacy of resting on their past glory might not bring people in or back. And when some of HD's most avid customers are switching to an entirely after-market crate engine, or dumping everything in the engine except the cases, or buying multi-$thousand extended service plans on a $40 K bike because it's a good bet the stock engine won't last 40K miles (who would accept that from a $10K car?), it tells you their stock price won't hold its value in the coming years.