The main problem with the DOM API is that when used from JS it's a pain, because it was designed largely by people wanting to do DOM in XML documents in Java on

The main problem with the DOM API is that when used from JS it's a pain, because it was designed largely by people wanting to do DOM in XML documents in Java on the server side; the use on the web was considered less important at the time. Many of the resulting issues (e.g. lack of use of options objects when it would be appropriate, numeric "enums" etc), flow from this historical accident.