The vast majority of your criticisms are unfounded. Nvidia contribute code to the open driver for their network hardware (see the commits) - you don't mention what version of Debian you're actually running, but if it's etch then it's hardly surprising that new hardware isn't supported terribly well. Try a more recent kernel. It's not clear what you expect HP to have done here - used older hardware to make sure Debian worked?
"the graphics don't work with standard Debian kernels and the standard Debian 'nv' driver" - this seems fairer. No 7000-series IDs have been added to the nv driver for some time, and 7150 is clearly missing. Naughty nvidia. No biscuit. But, again, hard to see what you wanted HP to do here - you bought a machine with an nvidia graphics chipset, and you're surprised that the open support is poor?
"I'll still need some firmware for the bcm43xx wireless card - and it is that firmware that made my previously ultra-reliable iBook into a flaky, power hungry psycho-beast." - no. Given that the firmware runs fine on non-Linux platforms, it's pretty clear that it's the (entirely open) driver that's at fault. Which is hardly surprising, given that it's had to be reverse engineered due to Broadcom providing no specifications whatsoever, but blaming vendors for using proprietary firmware is a bit much. Do you have the source for your CPU microcode? Your BIOS? The firmware that's in flash on your other wireless cards? Your hard drive? As a community, we haven't been sending a strong message to vendors that we want open firmware. Acting shocked that they then don't provide it is alarmingly unreasonable.
"GNOME doesn't yet work because of the proprietary crap" - the only proprietary crap you need is the graphics driver, and it's unlikely (though possible) that it's breaking GNOME. Perhaps you have another bug?
"I didn't think companies were still producing crap of this pitiful standard - HP: you stink" - this might at some level be linked to the fact that you paid 500 pounds, and as a result you got something made from cheap parts. That's not HP's fault. Their consumer hardware isn't designed to work with Linux. It's hardware that's designed to be as cheap and shiny as possible in order to appeal to home users who are then going to use it to download films and porn and animated mouse cursors in order to ensure that all their private data get sent to Russia. If it's supported by Linux then that's a happy coincidence. If not, then who cares?
Never mind. It's likely that your laptop is one of the machines that has some debugging hardware on io port 0x80, and as a result Linux's use of that as a delay port (despite the hardware's acpi tables claiming it as a motherboard resource) is likely to cause the machine to deadlock randomly if you do things like try to read the hardware clock or nvram. That's likely to cause you more problems than HP's use of Nvidia graphics.