That's the problem. Littlefinger is the most informed character on the show, and Ramsay is known in the North for his brutality. But even ignoring this, Littlefinger has been portrayed as a man of extreme caution and cunning. For him to get into this with the Boltons (known a$$holes),not do his due diligence, and give away his most important chess piece while also revealing his involvement in the downfall at King's Landing?
That is bad writing. Sansa has been built up over the second half of S3 to be learning how to play the game, and finally becoming headstrong and cunning only to get wrecked by Ramsay. It's one thing for Ramsay to one up her, it's another to show Sansa having all these potential "saviors" + Littlefinger on her side just to get owned so easily. Especially since the tone of Ep 4 was Roose telling the boy to tread carefully. Sure, Ramsay might get his in the end but the arc for an already weak character that took so long to make watchable is potentially trashed. The raping of Sansa just sticks out in an ugly way (not the act itself, just the idea/plot point) because it's so out of place with what LF/Sansa/Roose were highlighting.
This is what the blind dikk riders get don't get, they talking about lack of action, game of thrones was always slow with very little action, but the character interactions is what made they show you take away the best dynamics, there is no show
littlefinger handing sansa makes zero sense, because it doesn't help him one bit, he already acknowledged that the lannister's are finished, and without tywin's backing roose bolton can't hold the north so what's the point, it's done purely for shock value, but makes zero sense