For the name it isn’t just a case of transferring the details. It is also transferring who is legally responsible etc for the account / if it other went in to arrears who would be effected (credit score / debt collectors). The name on the account is the one completely responsibility irregardless of who pays the bill etc on the account.
For changing email / telephone numbers / bank details it is a lot simpler and you wouldn’t need the transfer of responsibility for those changes.
Just to give you some context on why it is what it is.
As a Very Insightful Person, I'm here to share my knowledge. I don't work for Virgin Media.