Date field not obey 'No default value' (defaults to current date) when within Field Collection or Paragraph

To reproduce:

Configure a filed collection that has a date field with Date popup any widget and set More settings and Values > Default Values > No default value

Observe that the field has default value of the current date.

This becomes a serious problem with non-required date fields: the user submits the form and the date fields are saved with the value of current date when the user did not intend to enter any data in the field. Date fields are often used with field collections in order to have a compound field that binds a date to other field values.