You could be right. I am sure the entire situation was a lot more nuanced then I portrayed it in my previous post. And I am sure many of the email admins for companies had a lot more localised pressing technical issues to deal with for the companies they worked with then having the time to ponder on the implications of email centralisation from other businesses.
I will always promote technological independence though. And despite the hurdles that come with running any technological service locally/privately whether it be an email server or otherwise it is ultimately worth it for those who need/desire the full control and privacy of ones own data. At-least that is my 2-cents.