One big problem is that if you're the base coach and you send him and he's out, you're the goat, even if you were playing the percentages correctly. And if he makes it, well no one cares about the base coach. So that guy's incentives are not completely aligned with those of the team/fans. But yeah, Gordon should have been running hard to first and then scored. Bumgarner would then of course have to pitch like 3 more shut out innings before the Giants would score and win.
Anyway, this play is the story for nerdy analysts and KC fans. For everyone else, it's just a footnote in the real story of the greatest postseason pitching performance in MLB history.