Well I think this is standard practice. Same with anything if you modify it then you are not going to have any technical support or warranty which is fair enough.
Lucky we don't need to do this anymore, and problems are just software issues rather than hardware from the way we mod PS3s. A USB device or soft mod is hardly a mod chip, and even then it's only through utter stupidity that it will get bricked in any numbers.
Sony have actually almost bricked my PS3 through a official firmware update before now though. The update which they claim did not even effect 1% of PS3's got me, the one where you update it reboots then boots the XMB without the XMB menu itself just the background.
Because I bought my PS3 overseas I was shit out of luck, and the only way to fix it was to reformat the hard drive in another computer, lucky I made an image of the drive in Linux and was able to restore it after re-flashing the newer firmware... after this I think they brought out recovery mode.
That was hilarious :(. So everything you do with your PS3 comes with risk... especially if you are out of warranty or have none, so you might as well hack it.