If the banking apps have a Terms of Service, you are free not to use the banking app.
To give a specific example, suppose a banking app wants to require location services in order to try to login. Some users can bypass or spoof this, (in fact that's what the thread is about entirely, and for that they root the phones.
Not all users who root the phones violate ToS, but it's a majority, or even a possibility, so they choose to disallow such usage.
If the banking apps have a Terms of Service, you are free not to use the banking app.
To give a specific example, suppose a banking app wants to require location services in order to try to login. Some users can bypass or spoof this, (in fact that's what the thread is about entirely, and for that they root the phones.
Not all users who root the phones violate ToS, but it's a majority, or even a possibility, so they choose to disallow such usage.
Pretty sensible stuff to me.