Originally Posted by Industrial

"the relatively weak braking" -Many cross bikes come with disc brakes now.

"awkward-in-traffic restricted visibility aero position" -Cross bikes have brake levers on the tops so you have the same position as a mtb.

"the relatively weak rims/tires" -Sorry, many MTBs have the same problem. They make plenty of strong wheels, rims and tires for 700c / 29er. Hell even Industry 9 makes 700c/29er wheels.

"uselessly high gearing which reduces acceleration 'snap' at intersections" -What?

A cross bike is basically a 29er mountain bike with in-between(road and mtb) gearing, drop bars, slightly narrower tires, braze ons for racks and fenders and a rigid fork.