My refutations of openings (early pawn sacs)

Your 'refutation' of the blackmar diemer is so hilariously deficient I'm guessing no one felt the need to address it. No one would play 6.Bc4 after 1.d4 d5 2.e4 dxe4 3.Nc3 Nf6 4.f3 exf3 5.Nc3 Bg4. Just so you know, 6.h3 is almost certainly White's best move in that position. That leads to the Teichmann defense, which has been mapped out pretty thoroughly and after 6...Bxf3 7.Qxf3 c6 8.g4, there's probably no advantage for Black there, but there are plenty chances for Black to mess up horribly in its hapless quest for an endgame with an extra pawn.

The most challenging systems against the BDG, both from a theoretical standpoint and a practical standpoint are the Lembergher defense (3...e5) and the O'Kelly/Ziegler defense (4...c6), and I anticipate the more dogmatic advocates of those systems will have some strong things to say about this opening (and perhaps me, for even playing it) quite soon. It's unclear if Black can concretely refute the gambit in those lines, but I think Black can definitely equalize by force a few ways and there is the potential for some lines to lead to =/+ endgames. I can't leave my engine running days on end for every move in every variation, to be sure of it.

I would play 6.Bc4 

Develops a piece to an agressive square, prepare's castling, and is sound positionally, so why is it bad.

You'll never be able to do it becaues I play it!