I certainly don't "know" but I can speculate. I feel like we tend to think of ourselves in a vacuum in that the Iridium's are/were very popular with us. The problem is, we make up a tiny fraction of the overall market. The vast majority of the market for DE blades is in the developing world where $.40 a blade is extremely expensive. To run some numbers, let's assume there are/were 10,000 loyal Iridium users here (first, that is likely very high and second, we are not the most "loyal" group... we like to experiment) and we required 100 blades per year. That is 1 million blades per year. They likely sold from the manufacturer at about 20 cents per blade. That is $200,000. That is before you 1) buy the steel and the packaging, 2) pay your employees, 3) pay for the machinery and upkeep, 4) I am sure there are few other expenses missing. You can expand out those numbers and it is easy to see that you need to be selling billions of blades, not millions.
That is my best guess...they weren't selling enough to really make any money. A lot of people hint that it is based upon P&G wanting to rid the world of quality DE blades, but I don't buy it. It is easy to read this site and think that product x,y, or z must really be going gangbusters based on all the love, but in the grand scheme of things, we are a pretty small population.
~It's not the razor...or soap...or brush...or water...or position of the moon...~