Have you ever noticed how the season of maximum abstinence coincides with the "blue months" when the winter larder is down to the last crumbs? The early Church fathers had a real gift for (literally) making a virtue of a necessity.

That said, the point of fasting before major feasts is to discipline the flesh and concentrate the mind while you're doing it, and to make the feast that much more glorious when you're done doing it. When you have eaten no meat and not much of anything else for six weeks, and spent an inconveniently long time on your marrowbones praying instead of watching TV, Easter is a delightful shock.

Advent has never been as effectively abstemious as Lent, not least because there's usually plenty of food at that time of the year. Also, the concentration of Christmas gift-giving and celebration on December 25th is quite recent in the traditions of western Europe -- your mileage may vary if you are Orthodox.