Well I guess not everyone in the world is as perfect as you. Seems reasonable enough that people would look more favourably at alternatives if they feel the 'legitimate' retailer is just screwing them. So they'd buy cheaper pirated DVDs, etc.
My experience with people who buy pirated DVDs* is not that they're thinking "Yes, I am doing this to protest the outrageous prices for these movies before the ridiculous retailer mark-ups; I shall purchase the DVD from illegitimate means thus allowing me to strike a blow against the corporations who extort us all for high quality entertainment" so much as they're thinking "Oh, hey X-Men: Days of Future Past on DVD for $5! Now I don't have to go to the theater!".
YMMV, of course.
*this is excepting, of course the "collector to collector" market buyer who is typically trying to find movies that aren't available in their country through any legitimate means.
Also works as well, if the legitimate price is higher than a pirated copy, not surprising people will go for that, is it ?