Nick -
I don't know if I like the X100, but my take is:
1. Fixed lens RFs, historically, were never positioned as serious tools nor designed to be. Consistent with their misogynistic era, they were marketed as dumbed-down cameras for women and positioned below any manufacturer's
amateur SLR line. Or dumbed-down cameras for rich men. Of the cameras you mention, only the Contaxes (and the Rollei 35S, Nikon 35ti, and the Hexar AF - all of which priced at the equivalent of $1,200 in the day) are really good optically. And none of the cameras you mentioned in your original post hold film flat enough to take full advantage of the optics they do have. Compact digital cameras are positioned no differently, but they are (a) smaller; (b) built to much higher tolerances by robots and individually calibrated on computerized test fixtures; and (c) do not have film flatness to contend with. An APS-C camera with microlenses keyed to the lens focal length is keyed to a different market altogether.
2. The difference in depth of field (regardless of whether you call it by its generic name or some new trademark) is negligible between an APS-C digital camera with an f/2 lens and fixed RFs, most of which had f/2.8 lenses. An APS-C digital will, for the most part, make better use of its wide aperture because the lenses are generally made better - and because it uses closed-loop focusing that can be arbitrarily trained on any point in the frame. The X100, having an ND filter in it, can also maintain "sophistication" in a much wider variety of situations.
3. APS-C sensors already crush the low-light capabilities of film cameras. This is even filtering down to the 1/1.6" sensors. Neopan 1600 deserved to die.
4. Pictures shot in color with 35mm cameras are vulnerable to mishandling in processing - to say nothing of long-term storage or what you are going to do when minilabs have completely disappeared and competent film scanners are no longer supported by computer operating systems (that will happen far faster than TIFF, JPEG or Lightroom go away - and if you own a Nikon scanner and a Mac Pro, it's already happened with 10.6). Scanners are already discontinued for the most part.
5. With most 35mm fixed-lens RFs, you get result that rarely exceeds 6 megapixels (since virtually all minilab output is now Frontier or Noritsu). Although you might argue that you get "4000 dpi" out of fixed-lens 35mm cameras of yore by scanning, the reality is that the system performance yields at or below 12mp - and for that, your ISO is pretty much 400 or less. And you go through a lot of time and effort to get that. Query why many pro 24x36 digital cameras are still 12mp.
6. The money argument does not make a lot of sense anymore. Good film and competent C-41
negative processing (meaning test strips run every day and not done at Costco) runs about $8 per roll of 36 (or even 24). Once you shoot 150 rolls of film (5,400 exposures in 36 rolls of 3,600 in 24s), it costs more to own the fixed-lens film rangefinder (assuming that RF cost you zero).* The money argument might have had some sway when digital cameras cost $5K, but we're competing with a lower-cost digital camera and film that costs almost twice as much as it did way back when.
*If you "paid" yourself even minimum wage to develop your own b/w, you are paying even more.
7. I think the discussion of "today's toy, tomorrow's trash" is amusing because fixed-lens RFs pretty much all ended up on shelves (and at thrift stores and garage sales) for decades. The only reason why they are cheap is because they were rendered obsolete by other film cameras.
In all, I think your argument (though posed in the form of a question) doesn't hold much water anymore. It would have been straight out of my thinking 7 years ago, but that's the better part of a decade and a geologic age in digital cameras.
Dante