As a business traveller you don't really care about the price as it's paid by your employer. So you'll take the fastest and most comfortable option. In many cities that's still a cab as they are much faster to get at airports than Ubers.

The other alternative are exec cars which Uber offers but which will often be pre-booked locally.

I think Uber could get many business travellers on board if they'd offer some rewards system (similar to airlines). Otherwise there's no reason to be loyal to Uber if a local cab or some other hire service (e.g. Lyft, Addison Lee in London) are faster to use.