"Tilted" Culture

In the past couple of months, and unfortunate trend seems to have formed. In about every other game I'm in someone inevitable says something along the lines of: "Don't do that, you'll tilt me" or "gg I'm tilted" or my personal favorite, "It's not my fault insert "op" champ here tilted me!" (this last one usually comes from someone going 0/8/2 or something).

My question is, when did this become a valid excuse? What ever happened to trying to control your emotions while playing? We aren't all Gnar. We don't spontaneously and uncontrollably erupt into some new hulk-like persona when we're mildly irritated. It's relatively easy to take a few deep breathes, mute someone, and focus on yourself. Being tilted has also become a popular copout for flaming. Someone can harass the team with their caps lock button mashed down and expect no repercussions as long as they explain that it's because "their tilted". Imagine if people walked around screaming at anyone who upset them. Personally, this conjured up the image of a daycare. I'm not saying that people can't get angry while playing or that emotions can't effect your performance. But it seems like people have accepted getting tilted as some part of gameplay, as if the only viable response to getting upset is to just surrender to your anger.

I'd like to ask what other people think of all this but I'm more than likely just going to get responses from people I've tilted by posting about this.