^^^ this
The chart in the OP doesn't tell anybody what the 'right' pressure is ... but if I know that I'd like 8psi for a plowed trail and it's -15*F outside and 60*F in the basement, I'll want to start with 12 psi. I know from past rides that *my* gauge reads 8psi and that works for me and the conditions, but I have not calibrated this gauge (and dropped it a couple times), so I'll likely get a different reading with a gauge at the shop ... but that doesn't matter does it.
If you're gonna argue against gauges because they are inaccurate, but promote 'thumb' and 'feel', you're being a little hypocritical. Both have one thing in common, it's all rider-specific.