I think that's increasingly true. A lot of people want to game the system and you mostly don't want to place the burden of what's reasonable on a low-paid customer service worker. So you set reasonable and (mostly firm) time limits and let the processes take their course. Should be some wiggle room of course. But it's not reasonable to offer lifetime replacements unless people are willing to pay the 2x to 3x prices that implies--which very few will.