On one hand, I can understand Black not wanting to give White the kind of game that the attacker wants.
On the other hand, as we have seen many times before, in declining the gambit piece(s) Black is exchanging an "objectively" won game for one where he is worse, if not losing.
In the following game, shugart at FICS, makes quick work of the situation.
shugart - amama
blitz 3 0, FICS, 2016
1.e4 e5 2.Nf3 Nc6 3.Bc4 Bc5 4.Bxf7+
White proceeds to play simple moves and out-play his opponent. He needed to face a greater challenge than that.
5...Qf6 6.O-O d6 7.h3 Nge7 8.Nc3 Be6 9.Nd5 Nxd5 10.exd5 Na5 11.dxe6 Nxb3 12.axb3 Qxe6
In typical defense-against-the-Jerome-Gambit-style, Black has returned the sacrificed piece - or, he would have, had he accepted a piece in the first place. Instead, unfortunately, he is now just down a Knight.
13.d3 h6 14.Be3 b6 15.Bxc5 bxc5 16.Qd2 Kf7 17.Ra6 Rhf8 18.Rfa1 Kg8 19.Rxa7 Rxa7 20.Rxa7 Rc8 21.Qa5 Qe7 22.Qa6 Kh7
A final slip, possibly in time pressure.