Most of the other points, while correct miss the big issue: the server should not store the password in case they themselves get hacked. If an attacker gains ac

Most of the other points, while correct miss the big issue: the server should not store the password in case they themselves get hacked. If an attacker gains access to one persons email then he gets 1 password. If he gains access to a server then he can potentially gain access to thousands of passwords. Therefore, having plaintext passwords makes you a target for attackers.