I'm not a civil attorney, Chris, but I believe you're misinterpreting what that disclaimer is saying. It's not a warranty. They aren't saying they aren't responsible for defects in the product; they are indemnifying themselves against any damage that the installation of their product, whether installed correctly or not, causes to your motorcycle when you put their rack on. They are also saying that, unless the existing law forces them to be responsible, that they aren't responsible for anything bad that occurs to you or your bike or to anyone else if you use their product, even if you're using the product in the proper manner. Like, say that another rider is following you and hits you from the rear accidentally, and is ejected from his bike and lands on the rack, severely injuring himself. Altrider is claiming that, absent and laws to the contrary, they aren't responsible for the injuries caused by hitting the rack. It's a liability disclaimer, not a warranty.
This is their product warranty from their website, that covered the actual parts they sell:
Hard Parts Warranty
AltRider stands behind all products we sell with regards to manufacturing defects in workmanship and material. We will repair or replace any components that fail in normal use within 1 year of purchase. Such repairs or replacements, including parts, labor and return transportation costs will be made free of charge to the customer. The warranty does not cover failures due to misuse, abuse, accident, incorrect installation, or apply to altered or repaired products. The entire part, including hardware, must be returned for evaluation unless otherwise noted. Warranty applies to the original purchaser only. Shipping costs for any warranty return are only covered for the country the original purchase was shipped to.
But, like most warranties, they're only as binding as the integrity of the company itself. If the company has no interest in investigating the actual cause of the cracking racks, and simply reverts to the "if it cracked you must have misused it" response, then relying on a warranty from the company is pointless. The only remedy after that is a lawsuit, but that's a big stretch for a product that only costs $229.00. I have a set of Altrider crash bars that I got on a scratch and dent sale, and I don't have any complaints about those, but just seeing how these racks are cracked would keep me from ever buying one. That's one reason I think threads like this are valuable to a consumer; if you think that the complaints are overblown, then that's cool, and you can feel secure buying the product. Alternately, if you're someone that becomes aware of the issue because there are photos posted on a forum, plus you get accounts from other riders as to how the company responded to their complaint, and feels that it's a problem, then you can use that info to guide your decision whether or not to buy one.