User experience

In an ongoing project, I heard the following in regards to user experience:

"It is good to maintain a consistent user interface between several related components even if the user experience is bad."

I understand the point being made, but is it really good to train the user to get used to a crappy user interface?

The possibilities:
1. Have a bad, but consistent user interface.
2. Have inconsistency in the user interface. One screen is a bad user interface and another similar screen is a good user interface. (Better or worse than #1?)
3. Switch all screens to have the good user interface (Best). The problem is that this won't happen due to lack of resources.