Re: Don't see how this helps any
a Jupiter-mass object out to 1 light year (63,000 AU), where it would still be within the Sun's zone of gravitational control. A larger object of 2–3 Jupiter masses would be visible at a distance of up to 7–10 light years."
Is that the sum total of your evidence? Quoting Wikipedia verbatim about the technical capabilities of WISE, rather than what is has actually been used for to date?
In other words you are completely ignoring the work that the WISE team have done, which they have announced now, restricting their claims to what may legitimately be claimed based on that work. Instead you have substituted what WISE is theoretically capable of, as if once you have the instrument you don't even need to turn it on to observe the null result. That isn't a scientifically robust argument, you wouldn't even accept that in everyday conversation.
Nemesis remains a fringe theory because zero evidence has been turned up in its favour. And it will rightfully remain a fringe theory.
You are overlooking several factors here. Firstly you choose to ignore the fossil evidence that led to the hypothesis being proposed in the first instance. You ignore the geological evidence to the same effect - sure it is a little sketchy but it is highly suggestive. You are completely ignoring the fact it has been published repeatedly in peer reviewed journals. You ignore that process of expert review, who concluded the theory had merit in order for it to be published, because you know better than them.
So, you ignore or dismiss evidence that is contrary to your position. You throw in irrelevant factors that do nothing to support your case as if they were final trump cards. You ignore the opinions of experts. Those are the hallmarks of a scientifically illiterate crackpot theory, not a properly published, legitimate proposal. Just because the theory naturally appeals to the "end of the world is nigh" brigade doesn't make it any less credible.