Capture API question

Hello,

I am sorry if this was discussed before but I was looking at the
Capture API FPWD and noticed that there is a section called "Capture
Input Selection"

http://dev.w3.org/2009/dap/camera/FPWD.html#formaccess

which shows that most of the functionality provided by the Capture API
can also be achieved using APIs that already exist in the Web platform
(i.e. <input>, File, <video>, etc). However, the spec does not have
any discussion about the reasoning behind adding a new API to do
something that is already possible. Since, to me at least, the reasons
for doing this are not completely obvious, I was wondering if it's
worth reconsidering the API or adding a note discussing the advantages
over using existing APIs.

Many thanks,
Andrei