There's a difference between saying the extent of something's effectiveness hasn't been established by existing research and saying that it is ineffective. I've read the publication you are linking to before and it is saying the latter without the evidence necessary to back up the claim.
I don't want to be "credentials guy," but I have a degree in cognitive science and I've conducted human subjects research. What you are saying is simply wrong.
That publication cites dozens of studies to back up its claims. Are you suggesting they are all invalid? If so, why?
Combined with the fact that this is basically a listicle ("quoticle?") clickbait from a mid/low-brow popsci website, with no analysis or synthesis, and you can pretty much throw TFA away, regardless of your side of what's shaping up to be a religious war here on HN.
If you say "the sky is green," it's not my job to prove to you it's not. It's your job to prove it is. You're the one making the claim.
But here is a (more politely worded than I) paper on the MBTI's ineffectiveness for your perusal: http://epublications.bond.edu.au/cgi/viewcontent.cgi?article... - simply googling "mbti external validity" will also give you plenty of explanation. I also recommend looking at the many studies that review cites, since its whole purpose is amassing information on whether the MBTI is effective.