Because if they did people would complain that they don't want a bike like everyone else. Then they'd strip them down and do jackass things to them.
THIS was a stock complete Pista Concept in 2005:
Exact same stock bike with bullhorns for comfort (actually my old bike):
Which people didn't like...so they made these things:
So, see? There is no winning this.
PS:
Honorable Mention:
