I've had a different experience to this. I've worked on ASIC's for over ten years and have had experience with nearly all aspects of the design flow (from RTL all the way to GDS2 at one point or another). I've taped out probably 20+ chips (although I've been concentrating on FPGA's for the last three years). Every chip that I've taped out has had extensive FPGA prototyping done on the design. This is in a variety of different areas too (Bluetooth, GPU's, CPU's, video pipelines, etc). You can just get a hell of a lot more cycles through an FPGA prototyping system than you can an RTL sim and when you are spending a lot of money on the ASIC masks, etc you want to have a chance to soak test it first.