> IMO it’s a matter of principle.

Eh? So Chrome should be used because Google has no principles?

Here's the Mozilla Manifesto:

https://www.mozilla.org/en-US/about/manifesto/details/

They explicitly state that they want the internet to benefit the public good as well as commercial use.

Principle number 9 is: "Commercial involvement in the development of the internet brings many benefits; a balance between commercial profit and public benefit is critical."

Mozilla clearly strikes that balance better than Google does.