There were people trying, but there are some real fundamental issues with the approach for general purpose computing. It's extremely hard for a compiler to know if some data is in cache, in memory, or way out in swap. Without this information it's very hard to know how long any memory fetch is going to take. If you're trying to run a lot of computation in parallel that has some interdependencies then this information is paramount.

It's kind of like trying to use a GPU for general purpose computation. Itanium should have been a coprocessor.