A lot of people use highsec as a transit route, simply traveling across it, much like they do in the midwestern United States. Many even choose to autopilot, barely paying any attention whatsoever to where are they are.
The introduction of warp bubbles would give people the opportunity to slow down, enjoy the scenery, and get to know the locals. Some might even stay awhile, and this would encourage player interaction and generate engaging content for everybody.
In keeping with highsec traditions, of course, shooting a warp bubble generator should turn your ship into a yellow flashy, allowing anyone to engage you in honorable PvP.