Re: One point in favour
It is a good thing!
I'm the human being, and I know what I am doing. If I'm asking a computer to add things, I want it to do its damnedest to find a way of adding those things, trying the most sensible things first (Do you see something that would be a valid numeric value, followed by junk? Ignore the junk, pick up on the number) and then getting desperate (Do you see a non-empty string? Increase the last character code and maybe propagate a carry to the preceding character), not just give up on me and go off in a sulk because the things weren't served on exactly the right shaped plate.
I know for a fact that it can parse the string "2" and get an integer, or maybe a floating-point number, because it was totally happy to do that without the speech marks. Sure, I could explicitly call a function to parse that string as a number; but as long as that's possible somehow, just the fact that I used the addition operator should be enough, and I only want to be told it's an error if the string cannot be parsed as anything that can sensibly have a number added to it. As long as whatever it does is deterministic
As for your "22", there is no circle of Hell deep enough for anyone who dares try to use + for string concatenation.