Because you understand that the world is not made up of absolutes and that .0001 does not mean success and .0002 means failure. So many forum members (not just here but all other cars) seem to think in concrete terms for everything (oil, gas, spark plugs, tire pressure, you name it) and that if you deviate just a tiny bit from the manufacturer's specifications your car will blow up. Clearly not true.
Someone above (or in another thread) mentioned "these are performance cars and need to be treated as such" but there's no rule that says a "performance" car needs to run at 10,000 RPM every time, every day forever. Some of us just use a car as a car. A fun car when you want it to be for sure but, generally, just a car. 87 octane, OEM plugs, regular steel rotors, non-ceramic pads, etc. Not gonna kill it.
I run 87 in general in my R because I'm cheap, I only go 6 miles a day, I don't floor it everywhere under load to produce lugging and pinging and I'm pretty sure my car will last a long time. If it doesn't then that's on VW for producing a modern car that can't cope with mundane driving.