I bet a lot more than 50% give up! Once you get back from holiday, you have to get back to normality, eg work, work and more work to pay for the next one. The form filing etc is a nightmare - all done to deter you - (the same with any household/car insurance claims.) Once you have done that, the next letters - could be months later - are either saying you did not comply with the guildlines or they want receipts, photos etc - by that time you are ready for your next holiday!!!!!
Finally, you give up but maybe it would have been better to have done that in the first place - it would have saved you a lot of stress. How many hours have you wasted writing, phoning or talking about your complaint? (Maybe more than the time spent on holiday) How many people do you hear of getting a positive outcome?
When I say 'you' I don't mean the original poster (who must have had an upsetting experience) -I mean 'us holidaymakers'!