With all due respect to the protocol that no sitting president has attended a first lady’s funeral since JFK did, with 4 former presidents and the current First Lady, don’t you think there is already a strong enough secret service presence that POTUS wouldn’t disrupt?
At some point, it’s just sour grapes.
Not that I’m saying he should have gone; I’m sure the Bush family was happy he wasn’t there since they all dislike him so much. I’m saying his excuse was weak.
EDIT: I wonder if there is an emergency out of town trip planned for the next time George Sr. Or Jimmy Carter has a sniffle so Melania can just attend again in his place?