As far as I can tell this is nothing to do with the MagSafe component but end user treatment of the power block. If the users pack their laptop and power block back and forth every day then you can reasonably expect the power-cord to get abused.

Personally I've had users return power blocks from all manufacturers that I wouldn't plug-in, and would only unplug wearing rubber soles.

Most road users treat the power block as if it is a bobbin, by the time they've packed it up 2-3 times a day for a year or so it resembles an old-fashioned phone cord stretched to its elastic limit.

(You can reduce the wear and tear by buying 2 blocks per machine so they never pack the one at home - just don't expect to get more than one back.)