Maybe because encryption using public key is much more CPU intensive and slower than hashing? Since you have users logging into the system all the time, you wou

Maybe because encryption using public key is much more CPU intensive and slower than hashing? Since you have users logging into the system all the time, you would need to encrypt the typed password in order to compare it with the record in the database, and this could put a great load on the server CPU if you have many users logging in.