They're blind-boxed trading figures. They've done bust sets as well, and if you think they're weird you're obviously a light-weight when it comes to just how odd the Japanese can be.
Passed that, the Japanese produce what is currently popular. Which is to say overkill-merchandising on what is popular. Which is also to say what is popular to THEM.
Ninja Scroll almost without fail always lands somewhere in the top 10 of a western anime fan's "Best" list. Not so in Japan. The movie was pretty much a wash-out. Therefore, no super sweet Kaiyodo figures with 25 points of hidden articulation. Not even a Revoltech, which other than mecha seems fairly content to rehash Evangelion and Transformers.
1/18 also isn't as "big" a scale with them as it is with us. I'm fairly certain there were Macross(or maybe Gundam) figures in 1/18 scale. They were static though, and hung around TRU forever.
But seeing as Gundam and Macross are inextricably tied to vehicles, they may see no point in doing figures in the scale. Because let's face it, how many collectors can or will shell out for a 1/18 Gundam( yes, i know about the 6ft Gundam statue)? And you KNOW that a 1/18 Valkyrie would be hugely expensive.
The thing you have to keep in mind, in the end, is that these are for the Japanese domestic market, and are to feed current trends. They could care less about western tastes because they aren't marketing them here. There isn't a lot of love for doing toys for a series past it's prime and without a current or upcoming revival. Though i thought i heard something about Macross coming back, and Gundam, much like Evangelion (nix that, Rei and Asuka) never go out of season.
Whoa, too much to read.