They changed the policy mostly I think because people had buyers remorse or just used the computer for a bit and then would return it when it was no longer needed. I believe the policy was mostly changed for all technology items because of CAMCORDERS. Consumers would buy one to tape an event and then return them(and most likely a lot of no/low budget filmmakers).There is Fry's electronics. Now that I have looked around it appears a lot of retailers have changed this policy. Basically I purchase Macs, Monitors, Home Theater equipment and Car Audio through Fry's since they are so cheap with massive selection. All other peripherals, upgrades, custom built PC's and cables I buy online.
Last I remember in the late 90's Circuit City, Best Buy, Good Guys and basically all retailers had a 30 day return I did not think they had changed this, especially with the competition with online retailers and discount stores like Fry's and Costco.
Frys:
Due to manufacturers' policies, Frys.com cannot accept returns or exchanges of certain products manufactured by the companies listed in the table below.
Apple, Compaq, Hewlett Packard, Intel, Mitsubishi, Sony and Toshiba products
If you read the info at the link I provided, you'll see their other restrictions.