It seems lame that you have to phone home to unlock a new device, but it's nothing compared to what they could be doing.
Perhaps they aren't all this onerous, but that really put me off of them.
Their security patch and update support for hardware is also abysmal.
My guess is that it's protection against stolen hardware? They can basically ban S/N of stolen phones, and the thieves can't unlock the bootloader and resell the device.
But yeah, it seems like a reasonable thing. Out of all the vendors, Pixel phones are by far the easiest to unlcok, seems like a weird thing to complain about.
This appears strictly worse than Google.
There is a huge difference between the two approaches.
If you're really worried about Google installing something sinister, it's already too late--the made they thing, they could have installed whatever they want at the factory. Anyway if you're installing a custom OS it's trivial to wipe on install.