If we removed every feature because someone might abuse it then we would have to give up on HTML and the web completely.  This one feature does no more to promote bad practices with SSL anymore than not having it will promote other bad SSL practices. 

Specifically about the feature, it was added to address use cases where Shared Hosters use a standard URL for providing SSL to their customer accounts.  While having the option may allow people to configure SSL in a less than optimal fashion; that is their choice.  This is still a big improvement over not having SSL at all.  In the end every user is responsible for determining their own requirements and the associated level of risk they are willing to assume and configuring their site appropriately.