I think it could be more down to the fact that you drive around all year in your car thinking it's all good, ...only to "occasionally" get a nasty shock when it come's to MOT time and they find a whole heap of problems you had no idea where there.
Tyre's, brakes & lights are easy to check yourself but a lot of people won't even have a clue what else to look at/check regularly on there car or before there MOT.