Jerome Gambit Declined: Puzzled

If you read about the Jerome Gambit Declined (1.e4 e5 2.Nf3 Nc6 3.Bc4 Bc5 4.Bxf7+ Kf8 / e7) in the recent "Jerome Gambit for Dummies 2.0 (Part 3)" you may have puzzled a bit at

White can part with his Bishop, instead, with 5.Bxg8, scoring 63% against 4...Kf8 and 91% against 4...Ke7. 

Does it really matter where the enemy King goes, once he decides not to capture the piece? Why such a difference in scoring  percentage for White?

The following game provides an answer. Again, risks abound in blitz games.

ImantsP - S-D-R

5 5 blitz, lichess.org, 2022

1.e4 e5 2.Nf3 Nc6 3.Bc4 Bc5 4.Bxf7+ Ke7 

The Jerome Gambit Declined. Black is feeling either suspicious or contrarian.

5.Bxg8 Rxg8

The proper recapture is with the Queen, but that may not be immediately apparent in a blitz game. I mean, why develop Her Majesty to an unpromising square and keep the Rook locked in?

In all fairness, 5...Qxg8 was found in only 3 of the previous 11 games with this line. Ouch.

6.d4 

Oh. But things can get worse. Only in the early drewbear - AAlekhine, Jerome Gambit thematic tournament, ChessWorld.net, 2007 (1-0, 33) did the defender find the best, but insufficient response, 6...h6.

6...exd4 7.Bg5+ Kf7 8.Bxd8 Black resigned