Another good reason is the MIPS based supercomputers of China. US government should avoid China to use MIPS architecture for reasons of national security.
<<One of the more interesting applications of the MIPS architecture is its use in massive processor count supercomputers. Silicon Graphics (SGI) refocused its business from desktop graphics workstations to the high-performance computing market in the early 1990s. The success of the company's first foray into server systems, the Challenge series based on the R4400 and R8000, and later R10000, motivated SGI to create a vastly more powerful system. The introduction of the integrated R10000 allowed SGI to produce a system, the Origin 2000, eventually scalable to 1024 CPUs using its NUMAlink cc-NUMA interconnect. The Origin 2000 begat the Origin 3000 series which topped out with the same 1024 maximum CPU count but using the R14000 and R16000 chips up to 700 MHz. Its MIPS based supercomputers were withdrawn in 2005 when SGI made the strategic decision to move to Intel's IA-64 architecture.
A high-performance computing startup called SiCortex, Inc. introduced a massively parallel MIPS based supercomputer in 2007. The machines are based on the MIPS64 architecture and a high performance interconnect using a Kautz graph topology. The system is very power efficient and computationally powerful. The most unique aspect of the system is its multicore processing node which integrates six MIPS64 cores, a crossbar memory controller, interconnect DMA engine, Gigabit Ethernet and PCI Express controllers all on a single chip which consumes only 10 watts of power, yet has a peak floating point performance of 6 GFLOPs. The most powerful configuration, the SC5832, is a single cabinet supercomputer consisting of 972 such node chips for a total of 5832 MIPS64 processor cores and 8.2 teraFLOPS of peak performance.>>