I have a 2001 Windrider Rave...it's a very fun boat, kinda like having your own roller coaster (I bought it used for around $5,000). I have heard that the Rave is sturdier than the Trifoiler, however the Trifoiler is a slightly faster boat. I know the Rave can be prone to pitchpole if the mainsheet isn't released quickly enough, and once pitchpoled it is unlikely to be righted without assistance from another boat. Also if the Rave was stored in freezing weather, there was a problem with the Rave's rotomolded polyethylene hull contracting more than the aluminum frame inside it, causing a tendency for the frame to break through the hull near the rudder. The polyethylene plastic hull could be plastic welded back toghether though, and Windrider came up with a fairly simple fix to prevent it from happening in the first place. The Rave is awkward at the dock, but once out on the water it is awesome. I just made an outboard engine mount so hopefully having an outboard will make docking easier for me as I have always singlehanded it.
Some people complain that parts constantly break on the Trifoiler, but I don't have any experience with Trifoilers. Also I believe the Trifoiler hull is more fragile being made out of fiberglass.
Maybe the manufacturers didn't market the boats well enough, or maybe some of the problems listed above scared off buyers, or maybe there just aren't that many people interested in sailing around at 30mph when conditions permit (the Rave can go faster but it's only designed to handle the forces at 30mph, and will likely start to dismast or break something by 45mph which is about the fastest I've heard of a Rave going).
The trifoiler was never a huge commerical success (<200 boats) as it is a limited use sailboat that needs 12-15 knots of wind to get it to go and it needs a beach with car access typically to get it launched. Never the less it is phenominally robust and well built and it is very fast - I have sailed at 35 knots (40 MPH) with a GPS. It does not break down underway easily but a good walk around is required before going sailing to ensure that all is as it should be. It is very stable at speed and also easy to sail - it is far more work to get in and out of the water than it is to use and it is a stable platform that automatically adjusts for altitude above the water. It does not heel at all even when pulling a gybe at full speed. The prototype still holds it's speed record in Class A cats at over 43 knots but it was a smaller boat with some differences in configuration over the stock hull.
Dan Ketterman is a VP at Hobie. He and his Brother Greg (the designer) still sail their boats regularly.
The trifoiler is still the worlds fastest production sailboat and a very cool ride.
The hobie trifoiler can only take a very specific amount of wind and barely any chop which is a semi-rare occurrence. They can only hold 2 passengers which is a very large limit. The rigging time for both of these boats can sometimes exceed an hour. All of the downsides to these boats don't justify making them despite their performance in good conditions.