It depends. If you have only traditional RPG/400 etc experience there are 10 programmers for each job, yes. But, in this marketplace, if you have experience with (traditional) RPG but also modern techniques like OO, Java, etc, you have lots of work for the coming decennia i assure you. These systems don't disappear, but they do have to be "modernized" and refitted to accommodate the changing environment. There is demand for it, but business do not know it's a modern system for which you can build modern software. The traditional RPG programmer will say something like "well XML and web services etc is too difficult, let's just use CSV and FTP like always". These days it's called "IBM i" and you can do about anything with it, there's even a port of node.js for example. It also has a binary compatible AIX subsystem which integrates with the rest. You can even call it (from a programmer's standpoint) - and it officially is - a UNIX system (POSIX compliant that is). Etc. When you see a green screen you see old software, not an old system that only supports green screens. And there are still more than 100.000 individual customers/companies using this system. And lots and lots of old RPG code, which only grows.
Are those WP's in the hands of customers or still in the sales chanel? I suspect the last, and i do not trust those numbers. It's MS after all. If you don't know what i mean with that last sentence then learn the "classics" first.
Btw, nu.nl is not a source, really not a source. Tweakers.net is also not a source, too biased (i know you didn't mention tweakers, just sayin').
COBOL and RPG, for example, on Mainframe / Midrange systems have native support for fixed point (decimal) types. It's the second most used type, besides the "character" types. Floats are seldom used in the context of business applications. Fixed point math is even directly implemented in hardware on Power processors. Always been like that on IBM platforms.