IIRC, while the 360 required hardware modifications, the later generations of mods were not that hard or that risky (of course, your definition of risky is dependent on confidence and skill level for those mods).
Addendum - the original XBox hardware mods were pretty easy too.
While it may not be risky for those of us who are comfortable dismantling hardware and soldering third party chips to the motherboard, you have to admit that is a much higher barrier to entry than browsing to a website designed to leverage the latest webkit exploit. I think it's enough to severely limit the size of a given platforms homebrew community.
The 360 hack I’m familiar with was just a reflash of the DVD drive firmware to always return data to the console as if the disk were legitimate.
This became a cat and mouse game between hackers and MSFT as MSFT started measuring things like latency and expected angles between blocks of data on the physical media to tease out whether the reported legit disk was actually legit or an imperfect copy.
I remember a few ban waves where people using modified consoles had their Xbox Live accounts shut down, then I stopped following it after that.
Addendum - the original XBox hardware mods were pretty easy too.