OP: "... I want it to just use the Black. ...I don't think it should be necessary to have an absolutely perfect profile available in order to just print black on paper, with no heroic attempts to match some exact shade of what it thinks the background should be. ... It can't be a clogged ink cartridge because I don't want it to use colors at all: just black for black! Follow me?"
Yes, calm yourself. We "follow you" perfectly. There is no need to get hot under the collar. You asked a very reasonable, but naive question. Literally thousands of R&D people have tried over at least a decade to get photographic quality black and white prints out of just the black ink channel of a color inkjet printer, and unfortunately, it just doesn't work very well with conventional color inkjet printers.
The reasons are (1) in the physics of droplet production and (2) the statistics of laying down smooth tones from a limited number of microdroplets per pixel.
The physics problem is that there is a maximum ratio that can be achieved between the maximum and minimum sizes of droplets (from the print heads) and rates of droplet production that can be achieved with stability and reproducibility. Think of the limited range of stable droplet sizes you can get out of a dripping faucet.
These maximum ratios limit the dynamic range of the print. If this were the only problem, with one black ink, you could get either (a) great blacks and a noticeable posterization / gap between the lightest grays and white; or (b) a nice smooth transition between whites and light grays but no really dark blacks.
Unfortunately, this isn't the only problem. The second problem is that each printed pixel is composed of some maximum number of microdroplets. For the sake of argument, lets assume this number is 30 (per color channel). Since we are trying to make B&W prints out of just the black ink in a color printer, this means we only have 1 color channel. In the dark and mid-tone areas, there are enough droplets to present a visual appearance of continuous coverage of each pixel. However for lighter areas, they may need to be only be a few droplets per pixel to approximate a given light shade of gray, but since there are so few droplets, your eye can resolve the small number of individual dots in each pixel and the resulting print looks more like newsprint than a fine art print.
Of course, as suggested above, there are some print drivers that allow the user to turn off all the color inks and leave only the black ink on. This may be acceptable for some quick and dirty, low cost text output, but not for a photographic quality B&W print.
The conventional way around this is a solution that printer manufacturers developed, and which you have just discovered: To provide spatially smooth patterns and smooth gradations in B&W tonality, to produce photographic quality B&W prints, the print driver uses a mixture of all the color inks to lay down a dark, but muddy base, and then adds flow from the black ink to further darken it and reduce any remnants of color.
If you really want to produce a photographic quality B&W print from only black inks, the solution is to use one of the specialty inksets that replace the color ink cartridges with a set of black and gray inks ranging from deep black to light gray. Obviously, you also have to replace the printer driver to get this to work. This approach is costly, but produces prints that are essentially indistinguishable from old-fashioned silver based prints.
Here are some references you might want to read on this subject:
http://www.northlight-images.co.uk/stuff2/?p=1532
http://www.inksupply.com/quadtone.cfm
http://www.inksupply.com/blackandwhite.cfm
http://www.inksupply.com/bwpage.cfm
http://www.quadtonerip.com/html/QTRrequire.html
HTH,
Tom M
PS - Should you not like to deal with the true level of complexity lurking behind such a seemingly simple request, here's a very easy technique that will likely improve your current results. Simply put a brightness/contrast adjustment layer at the very top of your layer stack. Click on the "Use legacy" option. Move the slider about 1/3 of the way to the right. This should force all the ligher tones to pure white and all the darker tones to pure black (...where "pure" really means "as pure as your particular combination of printer and printer driver can produce".
PPS - On the off chance that you are using some 3rd party or off-brand inks and/or paper in your printer, try a run with inks and papers recommended by the mfgr of your printer.
