I bought a car by sending out a document and evaluating salespeople’s written responses
Actually I didn’t because that would be an utterly ridiculous way to buy I car. The last time I bought one, I looked at it, I test drove it, I got a mechanic to look at it. You can do all of these things with Free and Open Source software, including getting a good look at the engine. This is much harder and sometimes not even possible with proprietary software. So why would you use an RFP process to purchase software, when you have the opportunity to actually evaluate it in a meaningful way instead.
If you are hoping for me to have an answer to this I am afraid I don’t. What I do know is that a typical RFP process discriminates against Free and Open Source software, mostly because we can’t lie. I am not saying that I know for sure proprietary ILS vendors lie, (although there are documented cases of their employees lying about Open Source before) but if people can’t see your code, you can say it does whatever you like. When talking about Koha, there isn’t this option. The code is there for everyone to see, the bugs are logged publicly, we have publicly archived lists, publicly logged IRC channels. What you see is exactly what you get, we can’t say “Koha will make your coffee” because you can check if that is true or not. So I guess this is a long winded way of saying, choose Free and Open Source software … we can’t lie to you.