I guess if you're looking for a reason not to buy a Kobo then you've found one. I never buy books from Kobo. I do have an account with them since I bought my first Kobo directly from them but I've never used that account. I've since bought 3 Kobos from Ebay and used some sort of invented email address to register it, not for security reasons but because I didn't remember what address I'd originally used. That worked just fine.
I think I used the name
barry@aol.com or some such to register my recent ones. That isn't a valid email address.
It's all a non-issue unless you're just eager to have an issue. Then, of course, it will serve.
Barry