Mounce on 2 Peter 1:20

Second Peter 1:20 is well known as crux interpretum. Bill Mounce has a good discussion of the issues here. For what its worth, I happen to agree with Mounce's conclusion. I offer the following four reasons for the the "origins" view (I prefer inspiration view).

(1) This view fits the context of authentication (v. 19). Peter never states how one is to properly interpret the Scriptures.
(2) Grammatically, v. 20 goes with v. 19 rather than v. 21 Thus, Peter is not talking about interpretation but authentication (Green, 2 Peter and Jude, 90).
(3) The conjunction ga,r is often used inferentially to indicate the basis of or conclusion for something previously stated. It is easier to see how the logic fits this view (Scripture is inspired → how inspiration occurs) rather than the other (Scripture must be properly interpreted → how inspiration occurs).
(4) While the term evpi,lusij can be translated as “interpretation,” it is never used this way elsewhere to refer to the interpretation of Scripture (Bauckham, Jude, 2 Peter, 230–31).