Startup Digest event submissions use similar method: no account, every login is an email sent to you. The problem I have is that I do use a password manager and like that much a lot more than switching back and forth of email and the site. If I go to your site, I don't want to go to my email...

It really feels like they want to solve my password storage problem for me, in a very opinionated manner without any alternative for me, and while it might be a good solution, it does not feel like one (for me).