Consider you posted your protonmail addy on a public www channel. You would receive quite some spam. It's like indirectly spamming protonmail, especially if you'd do this often, imho. That's why i chose the ten minute way, for example to let somebody i don't know write to my protonmail address. I wouldn't need to remember (or store) multiple protonmail addresses, change their password(s) regularly (optimally) etc.

It's just another layer of security and there are no after effects as soon as the mail address expires.
But hey, security isn't always meant to be easier, isn't it?