In Canada, for instance, federal government's patent policy research apparatus is essentially two people. Two.
Additionally, the epistemic academic work required to provide a proper critique of the industry is not well funded by public or private sources. On the private side, most interested parties are incentivized to be patent maximalists, while on the public side, applicants are basically pitching an argument to the legal academy that indicates that their central dogmas are so tremendously wrong so as to be unjust.
Additionally, the issues caused by a lack of patent reform are not acutely felt by the majority of individuals or industries, which means the benefit is concentrated while the pain is distributed. Representation at industry forums, accordingly, is slanted.
In the pharmaceutical space, for instance, WIPO had no issue with crushing access to medicine until there was a global outcry, and patted itself on the back when they introduced access provisions, despite themselves admitting the provisions were basically unused after four years following their introduction because the local industries and talent that they presumed were already dead and gone.
TL;DR: No inertia.
If done right -- and it could take 2 years or more -- we'll end up with a patent system that produces fewer patents (fewer people will bother to apply for 3 or 5 year patents, and fewer patents means less work for the overworked Patent and Trademark Office), fewer bad patents (because of the pre-issuance comment period), and even the good patents won't last longer than is necessary to give the innovator a reasonable return (at Internet speed, you don't need 17 years).