Date of Birth In Join Page overridden

I have found this issue for a while, not just for 7.1.4.

If you want to set 'Date of Birth' field in Join Page as a option, you will not check 'Mandatory' field and you also have to leave 'Minimum value' and 'Maximum' value' as blank(This step seems redundant because field 'Mandatory' control is enough). But the fields of 'Lowest age possible for site members' and 'Highest age possible for site members' in Profiles under  Advanced Settings will override 'Minimum value' and 'Maximum value' of Date of Birth and  'Lowest age possible for site members' and 'Highest age possible for site' are not allow to be blank. This results that 'Date of Birth' field in Join Page is default to mandatory. 

 Yes, there are some parts of Dolphin that still need the DOB to function correctly, that's why it defaults to mandatory.

If one does not have to be a certain age to join your site; which I would assume if I don't have to give my date of birth, then set lowest age to zero and highest age to 200.