Mike Bosworth's two books Solution Selling and CustomerCentric Selling talk a bit about RFP/RFQ's.
The authors note that most RF[PQ]'s are prewired and biased towards a preferred vendor. The client gives out the RF[PQ] so the client can say it was properly competed for so it can pass the approval process in upper management. If you are not that preferred vendor who was there from day one, you will most likely not win.
The author cites one anecdote of a big company that has a separate department that only handles RF[PQ]s. One day they decided to take some metrics over a time period. Out of that time period, they submitted 153 bids to unsolicited RF[PQ]s ... only won 3.
Some RFPs are definitely rigged. Spotting them is part of being a good consultant. See upthread for a deeper discussion on this.
"Most" RFPs are not rigged.
A company that submits 153 RFP responses and wins only 3 has a problem, and it isn't with the concept of RFPs. Perhaps their pricing is wildly out of whack. For awhile, there were things we did wrong with our proposals that cost us several RFPs. We figured them out, resolved them, and systematically improved our win rate.
There is no way that 1.9% (or even 5%) of RFPs are bogus.