I’ve seen many people doing impromptu spin workouts on CaBi bikes over the years. Maybe not high-intensity but they will sit on the bikes and pedal as though they were on a stationary bike.
As for the statement in the article about racing CaBi bikes, well, there was the (Bike Arlington?) team that rode CaBi bikes at the Crystal City Diamond Derby indoor cyclocross event last year. And there was the fellow who used a CaBi bike for the Nation’s Triathlon back in September. I would agree that CaBi bikes are not useful in a race. Except when the alternative is no bike at all. In that case, I would call the CaBi (Bixi) bike very useful in a race.