Tomato farmers use mechanical harvesters. The mechanical harvesters bang the tomatos around, and so can only be used on varieties of tomatos that are fairly resistant to damage. Therefore tasty types of tomatos that don't handle well are not grown commercially.

You can find more consequences of mechanical harvesting of tomatos at [link|http://www.lclark.edu/~soan221/01wlc/AgTechnology/harvester.htm|http://www.lclark.ed...ogy/harvester.htm].

Cheers,
Ben