Why weren't they popular.
Somebody has asked this about every gun that has ever been discontinued. (especially the people who's job was to design, build, and sell them!
)
There are many factors involved, and they go beyond just the gun's actual performance.
Timing is one of the big ones. So is appearance. So is price.
And also, what is the competition??
What does the buying public want most, or just want, today? What will they want tomorrow??
Can you sell enough to not only justify the cost of making them, but also turn a profit??? If the maker doesn't guess right about all these (and several other) things, the gun goes out of production.
You've got a rifle built for a niche market. And out side of that niche, its just not very appealing to many people.
As a SWAT/military sniper rifle, it looks to be a good fit. People who want that look (and features) would be interested. The rest of the buying public, not so much...
Its optimized to be really good at one thing, and so isn't the best at other things. And when the bulk of the market wants those other things, you don't sell many 0f the guns without them.
The firepower guys don't want bolt actions. Hunters are about performance, not just of the round, but of the total package.
And that includes the size, weight, length, and appearance of the gun, along with the caliber it's chambered in.
If it's "too long" or "too heavy" its not going to sell well. Nor will it sell well if its "too ugly".