Maybe different areas of expertise aren’t equally valid, and even good experts often can’t see the forest for the trees in terms of developing actionable advice.
The only recommendations to limit fish that I have seen are due to mercury exposure risks:
https://www.fda.gov/food/consumers/advice-about-eating-fish
Coal burning and incidental industrial releases drastically increased the amount of mercury in surface waters over the past century. The released mercury gets transformed by bacteria into organomercury compounds which are lipophilic and concentrate up the food chain, meaning that predator fish like tuna and swordfish can contain orders of magnitude more mercury than the water they live in.
There are plenty of fish with much lower mercury levels (like salmon, trout, and sardines):
https://www.fda.gov/food/environmental-contaminants-food/mer...
You can eat all the salmon you want without worrying about mercury, and I haven't seen government advice to the contrary.
Thats tantamount to a recommendation that fish should comprise a minority of your protein, which is backwards. It’s almost certainly healthier overall for fish to be your primary protein source and to eat red meat, chicken, and pork sparingly. How many servings a week of fish do you think Japanese kids eat?
Who was lobbied? The lobbyists can’t publish things in the Federal Register. How it works is they try to influence the experts at the agencies to support their position. That’s what lobbying is. It’s all laundered through experts both in the private sector and the government.
The real winning move if you can afford it to pay for a bunch of academic labs who won't at the margin publish stuff that's bad for their sugardaddy. This way the lawmakers, the bureaucrats and the public discourse is all built upon numbers and information that is favorable to you. So then when those officials you bought make the "right" decisions they can do so in comfort knowing that their decisions are backed by the numbers.
Yup. Scientists have bills to pay too.