I should not be able to have access to see users passwords.... It should be encrypted and hidden from anyone ever being able to access it. That should be default and obvious.
Regarding displaying password or not, admins have different cases for whether they want to or don't want to view passwords. If you prefer not to, you can disable here: Logged on as admin -> Setup / Configuration -> Hide customer passwords in aMember CP
In any case, this is fixed in upcoming aMember Pro v4 - passwords are not stored in plain-text format at all. Regarding v3 - yes, we really should not be storing it in plain-text, but it was necessary to make 3-rd party scripts integrations possible. It required a lot of efforts to implement it without plain-text passwords...