It's a weird psychology...
I think that it all comes from being told in the media that flying is safe and that it is all "CAA approved" and that nothing can go wrong.
This results in an attitude of "nothing will go wrong to my aircraft" and so they apparently don't have to worry about expensive maintenance.
The fact that the carefull and therefore expensive maintenance is what keeps flying safe seems to get lost in the nice walm feeling of only paying £800 for an Annual check!