Earlier quoted context omitted.
That raises an interesting point -- the original MIPS ISA hasn't been patent encumbered in quite a while (and even then, only two non-essential instructions were patent protected). Why should a person is this unknown ISA instead of MIPS?
I think it may be to avoid any political/legal issues - despite the patents having expired, MIPS still sells ISA licenses. On the other hand, RISC-V basically is most of MIPS (but most RISC ISAs are very similar anyway). They also avoided the patented instruction issue completely by removing all alignment restrictions from the regular load/store; probably a good idea, with memory bandwidths being the bottleneck now a…
That RISC-V resembles MIPS is a testament to what was good about the MIPS design, however if you look closely you will find the many ways in which RISC-V is different.
Truly, the specification is highly readable and the footnotes enjoyable. Having implemented multiple MIPS cores and so far one RISC-V core, I'm deeply impressed with the care that went into the design.