Allow me to explain: I love words. Finding the perfect phrase to describe a situation makes me absurdly happy. Conversely, using my mad language skillz to make a joke is also something I pride myself on. That is why it saddens me that the pinnacle of humor is to use a prefabricated line to turn something innocent into something sexual.
Not that I'm against turning people's innocent statements into lewd remarks and making them seem a pervert, I'm for that by all means. But where is the creativity? In the spirit of originality allow me to weave a metaphor:
In days of old humans worked for food. Either working the land or hunting prey to satiate their hunger, the calories earned were just enough to pay back the calories used to acquire the food. Today its a different story:

Thus, we have grown fat and lazy. "That's what she said" and other prefab jokes (Pwnd, LOL, Any un-ironic movie quote) are to humor what hotpockets are to food. Lost are the days of wit where Winston Churchill could dazzlingly outwit a crotchety aristocrat after having enough Scotch to kill a horse. Instead we are left with clashes of wit being fought with Internet memes and movie quotes.
In conclusion, that's what she said jokes are ruining society. It is simply too much to swallow.