You just made me ask myself the question, “has Jon always been a complete idiot?”
The answer surprisingly is no:
- He took Tyrion’s advice and helped train the Night’s Watch brothers who tried to kill him in the first season — they ended up becoming his most loyal friends.
- He took Tyrion’s advice about owning the term bastard to protect himself from getting hurt. Alliser Thorne only provoked him when he insulted his family.
- He took Quorin Halfhand’s advice and became a mole in the Wildlings army.
- He did the smartest thing any man could do in that cave with Ygritte.
- He lied — LIED!!!! — about the number of men manning the wall at Castle Black. That may be the only lie he ever told in the entire story (except maybe the part about where he learned the Lord’s Kiss).
- He knew Ygritte wouldn’t kill him because of their love.
- He learned from Karl about fighting dirty, and killed the Thenn with a hammer.
- He made the right decision (from a strategic and political standpoint) to let the Wildlings through the wall, and was saved by the Wildlings and Wun Wun a couple of times.
- He begged Mance Rayder to bend the knee to Stannis, arguing that one man’s pride should not be the reason thousands of lives could be lost. (A piece of advice thrown back in his face by Daenerys in the second of three caves.)
- He let Samwell go to the Citadel, because Sam would gather invaluable knowledge (like the 17,582 shits taken by that Maester who chronicled the Lyanna-Rhaegar wedding).
- He gave Sansa the rule in the North when he went to Dragonstone, knowing she would be a wise leader.
- He convinced Daenerys to sail with him to show the people solidarity (as well as some other side benefits).
That’s a lot of good decisions, including some that indicate a rudimentary understanding of politics.
What we can see is that Jon’s decisions have a decidedly moral foundation, so when he deals with someone who is honorable, things work out pretty well.
When Jon deals with someone who is immoral or evil, he gets fooled easily.
Finally, when Jon is in the heat of battle, he’s good at fighting and leading, but no so hot in seizing opportunities. If you remember, it was Grenn who lied to Janos to get him away from the wall where his cowardice and lack of leadership might have allowed the Wildlings to win the battle. And, of course, on the suicide mission, he could have ended the Night King’s threat by directing Daenerys to go into full Mad King mode.