Inconsistencies with .value and .defaultValue properties

Please reference my following two StackOverflow posts:

http://stackoverflow.com/questions/40431329/html5-javascript-change-to-defaultvalue-property-injects-value-attribute

http://stackoverflow.com/questions/41398247/html5-javascript-removeattributevalue-removes-defaultvalue-too-why

I'm unclear of why the handling of .value and .defaultValue are inconsistent across various form elements, and think it might be worth standardizing their functionality to prevent confusion.