A company's purpose is to be profitable, ethics side is largely irrelevant.

Maybe so, but companies such as Proton's biggest asset is their reputation...a reputation of being privacy-focussed. Without that they are nothing, and they know that. As a result, they try to live up to that reputation as well as possible.

Being as it was started by Sir Tim Berners-Lee (among some of CERN's other founding fathers of the web) is just icing on the cake.