I guarantee that MAC has figured returns into their model and has likely decided that hype with a small increase in returns generates a larger profit for them than lower hype with less returns. Given that I buy bucketloads of product at full retail price, returning a couple of products a year doesn't come anywhere NEAR making me a cost to others. I'm pure profit to that company, and so is everyone else who buys virtual Pro quantities at full retail price. MAC would rather me buy more and return the odd product than err on the side of caution and buy way less.
I don't doubt that there are some who order way more than they intend/can afford to keep and then return heaps of it. Would someone like that impact the bottom line negatively? Yes, of course. But the mega-buyers here who return the odd lippie because they just can't make it work for them (after buying and keeping 30+ other products during the year) aren't hurting anyone. It would be nice to never get it wrong, but that's almost impossible and MACs business practices certainly don't help.
I've done this kind of marketing/product/distribution analysis professionally for more years than I care to admit to.

I stand by my opinion - if you didn't like the lippie you had to order online the second it appeared or risk not getting it at all then you should have no qualms about returning it. MAC knows very well that will happen sometimes and has chosen to accept that risk.
I'll go out on a limb and say that I'm all but certain (even without unit costs and modelling) that Pro customers who buy large quantities and then sell to retail customers at full price cost MAC WAY more in lost profits than a retail customer who does an occasional return. MAC sells to Pros at deeply discounted prices - those products are then sold at full retail price (if not more) to retail customers who were unable to get the products directly from MAC. The Pro member makes the 40% and MAC loses the difference.
MAC management could (and should, IMO) do a lot more to crack down on that kind of abuse. It's a way bigger fish to fry.
Let's see now...how many people have I managed to piss off?