Not sure the graphic is supposed to be perfectly to scale, and not sure its really something to be upset about. Obviously its hard to depict all of the planets big enough so the laymen can see them and still visualize the vast size of the Oort cloud. So I doubt it was ever supposed to be legitimate scale.
Planet 9 is either there or it isn't. So unending articles and research papers about its existence or lack thereof is to be expected until the area its theorized to occupy has been extensively studied and ruled out, or we find it. Until then neither side is gonna quit talking about their theories and personal feelings on the matter.
So I just sit back here and enjoy the show.
Personally I think its a smarter endeavor to look for the possible planet than to entertain unending plausible theories about intergalactic visitors that we'll never be able to prove. The only thing provable is whether it's there or it isn't there and I guess whether the math even makes sense going forward after learning new things about orbital mechanics in the future...but I still prefer the search. With our current tech we should easily see light reflecting from an object of that size to fairly far out if we look in the right place, especially in IR. So while its a huge task, I say observe the entire window of where it could be throughout the next couple decades and chalk it up as a success or failure depending on whats found or isnt found.
Personally I don't think its there, but the smart money is on looking for it; not in entertaining endless theories about endless possible phenomena that could give us the same results as we see now with eKBO's and high inclination centaurs.
Edit: fixed some autocorrects
You're a little too quit to slap back sometimes, because I don't think you really understood all that I was saying.
For instance: I never said to avoid theory or planetary dynamic modeling, I said:
"Planet 9 is either there or it isn't. So unending articles and research papers about its existence or lack thereof is to be expected until the area its theorized to occupy has been extensively studied and ruled out, or we find it. Until then neither side is gonna quit talking about their theories and personal feelings on the matter." Obviously eluding to the fact that both of these things from both sides will continue to be debated.
I said this because you're often refuting the veracity or legitimacy of papers contrary to a planet ix hypothesis. Even to the point of dismissing one due to the scale of a chart of the solar system that had absolutely nothing to do with the paper itself.
You also jump to the extremes when defending that the planet could be harder to find than it should be (dense tholin surface causing low albedo, or positioned in a dense starfield and there for hard to discern from further objects), when in reality some of the very papers you've cited here predict absolute magnitudes well within current tech scope for the planet; and considering it is predicted quite often to be a massive planet, very possibly a gas or ice giant, a dense tholin surface isn't as likely as a cloud layer which would be much more reflective. Extremes are reached for by the desperate and I don't think we're to that point with this search yet. Outside of visible light, with its projected size, IR is probably a good bet for how we'll find it if it's there.
You're also correct on this point of course, it could have an incredibly low reflective surface or lie in a dense star area of the sky; I just don't find that very compelling without significant evidence that either one of these is true.
You then misunderstand my point about:
"(not) to entertain unending plausible theories." And no, there are not unending plausible theories."
I wasnt talking about your theories, I was talking about the skeptics who continually theorize larger astronomical visitors to the outer solar system that could account for current eKBO's and high inclination centaurs; and yes, they appear to be near infinite since another pops up every few weeks.
But yes, I should have used a semicolon in my comment about IR to separate two different thoughts with more context, or written it in its own sentence.
My post was mostly to agree that we should be dedicating sky survey time to this project and that I believe looking for it (theoretical modeling included) is the better bet.