I've grown so tired of repeating the word "Google" every day that I don't even use my Google Home devices any more. Why not allow users to change the wake command? In the meantime, I will go back to Amazon's devices, which do allow you to change the wake command.
Although the Google Nest team do monitor this community forum it is also best to send feedback directly to the team.
Please also leave feedback for the Google Nest team requesting that you would like to see this feature introduced.