Once a taxonomy has been added to the document type it can't be removed through the doctype editor

Reproduction steps:
1. Create a new document type.
2. Add a taxonomy for that.
3. Save and commit.
4. Generate Beans with BeanWriter.
5. Open the doc type editor.
6. Edit the doctype.
7. Try to remove the taxonomy by pressing on the "x"

Expected result:
I'm able to remove it.

Actual result:
Nothing happens.