Where have all the Ninjas gone?

I recall, upon returning to the U.S. in the year of our Lord, 1985, ninjas. Not any specific ninjas, mind, but ninjas galore peeking out from a million places. The world, (or central California, at least) was absolutely infested with ninjas. Turn on the telly, walk down the toy aisle, or enter the video store, and ninjas came flying feet first at you from around every corner. There were white ninjas, black ninjas, grey ninjas and red ninjas. Rambo faced off against ninjas in his cartoon, (if you were so fortunate as to catch that particular artistic marvel,) as did G.I. Joe. Cobra was about half staffed with ninjas, if memory serves. There were teenage ninjas, little kid ninjas (sometimes in groups of 3,) caucasian ninjas, black ninjas, and of course Asian ninjas. Well, Japanese ones, anyway. The burning question of whether a Chinese person could ever become a ninja never seemed to get addressed - I have to assume that the ninja schools turned away all the Chinese aspirants, telling them to "Go kung-fu yourself," or something like that. Ninjas were so ubiquitous in the mid 80's that we couldn't even confine them to one species, (witness Splinter the rat, and the Turtles,) let alone a single ethnic group or neighborhood. There were ninjas-a-plenty in Beverly Hills, if you recall. Enough so that they formed a club, and went about ninja-ing things. (I can't be more specific because I don't really know what ninjas did when not hanging from ceilings, moving incredibly stealthily, or throwing small, very sharp objects that result in instant, fantastically silent mortality. I just did a web search, though, and actually found an answer to the question -
Q: "What do ninjas do when they are not cutting off heads?"
A: "Most of their freetime is spent flying, but sometimes they stab."
I am glad we got that sorted out.

My point, however, is that something very dramatic has happened among the ninja populations over the past 20 years. Today we have far less ninjas than we used to. I attribute this to one of two things (or maybe a confluence of both factors.) First, global climate change, and secondly, the return of Pirates. I will explain in greater detail later.