Then others join in to say they work for or have heard of some research institute or whatever that had proprietory ISA cards and that they had to spent $200,000 to switch over to a few PCI cards that don't work as well.
I guess you are talking about me. Here are some examples:
1) I'm a chemical engineering grad student. We just moved into a new building last July and had to move all the equipment along. The department decided to upgrade all the computer equipment in the labs (including the chemical engineering operations lab). Well each experiment is controlled by a computer - ISA is the king of cards to do this with. Each PCI card costs a bare minimum of $1000 (plus thousands more if that equipment needed extenders or adapters). Multiply that by 20 experiments and you get into the $100,000 range just because ISA was not available in any major OEM computer. So instead they switched to a whole new type of control that cost $188,000 for the one lab and they still have a full time employee working on software to get the stuff up and running with the new equipment.
2) A little known fact on how Windows works with cards is that ISA cards can be accessed at a much higher frequency. Suppose you wrote a program with a loop where you read/write from an ISA card. Even the slowest pentium computers can run that loop on an ISA card roughly 1 million times per second (note for reads the issue of a slow computer being able to store 1 million pieces of information per second is a problem though). Do the exact same thing with a PCI card - you'll get roughly 500 reads/writes on a slow Pentium and I can get up to 2000 reads/writes per second on a 1.7 GHz Xeon. At least for my work, that is a tremendous disadvantage that PCI has. It is a Windows problem, but drivers don't exist for Linux for the vast majority of industrial cards. Heck I'd be willing to write a program to run from DOS on a new computer (and I have in the past for specialized equipment) but I don't have a clue on how to access a PCI card from a DOS program (note: I'm not a trained programmer, so maybe there is a way).
3) About twice a month we get posts here from new people joining Anandtech specifically looking for ISA. So there are people out there desperately looking for it. The most recent one was some sort of mechanic wanting ISA on a notebook (which is certainly not going to happen).
4) Here are some links to ISA products from companies that are better performing or far cheaper but I cannot use and must settle for PCI:
Keithley (which is where I got the 2000 vs 1 million numbers),
National Instruments, and
Ocean Optics (which has an ISA card that does its job in 5 milliseconds versus an external USB card that takes 13 milliseconds).