Hans:
T2300 and TNE both suffered the same issue, and similar fan reactions...
Both of them take and have very different setting assumptions from CT/MT, AND have very different rules systems, at the same time.
If TNE had used the same mechanical engine as MT, it would have been received very differently (and quite possibly with less hostility). Likewise, if they hadn't tried to impose the New Era, and had instead simply made it hard times with the new rules, that too would have been an easier transition. Heck, in terms of setting assumptions, removal of T-plates broke the profitability of the "classic" small merchantmen by increasing times to/from jump point from about 1/2 a day to about 3 days... and thus the jump cycle went from "6 days down, 8 days travel" to "5 days down, 13 days travel"... from 2 jumps per month to 1.5. Plus it made even 0.1G viable for taking off from any terrestrial planet generatable with the system.
2300 was likewise a radically different setting and a radically different ruleset (It really appears to be TNE's Great-Grandaddy, and CT's grandchild via some unpublished intermediate stage).
Heck, the TNE->T4, CT->T4, and MT->T4 jump likewise suffered some hate because the core wasn't capable of running the CT/MT classic/rebellion eras mechanically... it only covered to TL12 in the core. The setting revision to a TL12 limited era coupled to a ruleset nerfed to TL12 was a major issue for a bunch of people. FF&S2 being "broken" (by printing error) didn't help anything.
Mongoose's decision to be mechanically close to CT/MT is good for backwards compatibility, and thus maintains the value of older materials and allows the new stuff to be used with the old games.
But their decision to "revise" the OTU at the same time is evocative of the TNE and 2300 issues.
Heck, CT->MT had some issues... but at least there, most people familiar with CT Bks 1-7, Striker, and Supps 8 & 11 could see where it all came from. The Rebellion didn't get hard-coded into CGen, either... unlike TNE.
Hunter's decision to use "just post SRW" was dicey... but it was pulled off by being close enough time and tech wise, and far enough distance wise, to make the setting differences work, and since it was targeted for a group wanting a "D20 flavor"....
GT would have worked just as well if it were set in 1101... perhaps better, even... because the tech and setting are in the classic mode, and it's aimed at GURPS fans. It changed only one element.
I've noticed often in other games: Change the Setting OR change the system with an edition change, or you get angry fans.