It seems those most put out are players looking for the 'best' class, saw the DF profits stripped from discoverers and cried. I chose dico because it appealed most to my play style.
My fleets still go out and come back. Pre update I easily made more from a res result than a DF by x10 at least. Get enough of those and you don't care about DFs. My fleets have cargo capacity of 266kk, largest find ever was 101kk metal. Average is around 11kk. Put time in, play the game and profit will follow.
I've been dying to ask this stuff: Is there a thread for discos concerning everything expo? SI points vs outcomes. I have seen some discussion of various fleet compositions to attempt to influence the result. Somebody said GF won't publish expo weightings which seems weird.
While I agree with the point you brought up, I feel it is coming from a bit of a bad understanding of the underlying game mechanics in question, as I read the rest of your post.
Sending 266kk capacity is a waste - your finds are capped and the numbers and formulas are well known by now. https://expocalc.universeview.be/
Enter your universe data here, speed is economy speed not fleet speed, check Discoverer, insert at least 1 Pathfinder, then adjust other ships. This calculator is correct on resources but incorrect on fleet finds, but it will do the trick to get you to understand why sending 266kk is a waste and why your best find was around 100kk metal.
As for various other interactions, approximate chances of results, fleet compositions, visit Grandpas thread and have a good read, everything is there, but it is outdated with the new balance patch as it mostly concerns battles. Expeditions : a study from the French community
If you do some calculations with the provided excel sheets and the such, you will see that your average 11kk finds are peanuts compared to literal Billions that were made during the shitfest era of pirate hunting. And this brings us to why your initial point is valid - people saw the opportunity to exploit an insanely imbalanced game mechanic to make unreal gains, and now as it got removed, they whine. It did very much devastate the game when it comes to pretty much every old server, so it is partially understandeable to see everyone get riled up. The damage done to the playing experience on every server affected is beyond repair.
Not to worry though, as GameForge did make sure to also devastate the new servers experience, starting with Sombrero. #1 now has well over 1 million points, 48 hours in. Hilarious.