[mcguire]

"But they have no requirement -- and I would argue no business -- to wipe a non-company device just because someone added a corporate email account to it."

Personal devices are excellent attack vectors if allowed on the internal network unmanaged. The alternative is not accessing internal resources, email, etc., unless the employee is given a company-owned device.

[chipotle_coyote]

I'd genuinely argue that if the company's worried about that, they should either (a) to disallow personal devices on the internal network, period, or (b) find a management solution that does not involve putting data they do not manage at risk. Just as my personal physical property does not become company property if I am on their physical property, my personal data should not become company data if I am on their network. I understand that segregating data that way may be a hard IT problem, but if they can't do it, the solution should not be "welp, we control your data now."