That's because it's a better ISA than ARM or x86 (both of which carry loads of legacy crud) and the early MIPS-related patents have also expired. In addition, there are loads of MIPS textbooks out there.
There are still lots of markets that use MIPS. In addition, China seems interested in a national ISA and seems quite invested in MIPS. I wouldn't write it off just yet.
I would say that MIPS is the only ISA that has definitively proven itself in everything from tiny microcontrollers to multi-core, SMT (hyperthreaded) monsters that run most of the world's networks or the upcoming Chinese petaflop supercomputers.
In the CS department, they do teach a limited subset of MIPS with a Java simulator. But the Engineering labs switched from m68k to ARM about two years ago despite the latter having a much more complex instruction set because of a large hardware donation. :(
There are still lots of markets that use MIPS. In addition, China seems interested in a national ISA and seems quite invested in MIPS. I wouldn't write it off just yet.
I would say that MIPS is the only ISA that has definitively proven itself in everything from tiny microcontrollers to multi-core, SMT (hyperthreaded) monsters that run most of the world's networks or the upcoming Chinese petaflop supercomputers.