I've always equated MGS3 being the RE4 of the series. Only for the fact Big Boss kinda ruins the series going forward.
I think it's more that Kojima abandoned everything that was good about MGS3. What was cool about MGS3 was that everything in it was period accurate, for the most part, and, with the exception of Ocelot, it didn't lean on previously established supporting cast, it didn't fall into the prequel 'trap' of over-explaining everything that's identifiable with the series.
Then he does Peace Walker and you've got Miller and you've got Otacon Sr and you've got Outer Heaven before Big Boss would have even founded Outer Heaven, and you've got technology that wouldn't have existed in 1974 but it totally exists in Peace Walker because Big Boss' ragtag band of super mercenaries developed it. Then you get into MGSV and you've got Baby Liquid and Baby Psycho Mantis and you've got fucking Metal Gear REX but it looks more technologically advanced than the 20 years younger Metal Gear REX. And you know, Kojima just abandoned fidelity to the setting and fell into the prequel trap, except that he had to change the characters and the setting to make it all fit
Is it really cope when there's a clear shift when he leaves?
The bulk of the plot in the trilogy is in the codecs, he wrote those. And then from MGS4 it's mostly in cutscenes and they're written terribly. No witty dialogue, and no gravitas.
It
is cope. There's numerous articles and interviews that detail exactly what Fukushima did and, moreover, point out that he wasn't even brought in until late in the process on both MGS1 and MGS2. Kojima created the characters, the themes and the settings before Fukushima was even brought on.
Also, he worked on MGS4 (he's credited in the
TGS trailer but not in the final game).
Also also, the rebuttal to 'Fukushima is the secret architect of MGS' is Metal Gear 2: Solid Snake. Play that game and you'll realise that MGS is basically a soft remake. A lot of the gameplay elements, a lot of the plot points, a lot of the characters (or at least, the character types), they're already there in MG2. And Kojima wrote it.
What the 'Tomokazu Fukushima is the secret architect of Metal Gear' theory is, and you see this a lot from people like Razorfisting, it's become fashionable to hate on Kojima (to be fair he has become immensely pretentious and he's waay too in love with Hollywood) but people like Razorfisting have cognitive dissonance because MGS1, 2 & 3 were objectively good games. So the way they rationalise enjoying them even though they don't really like Kojima is 'Kojima didn't really create them. Some other, unsung, Konami employee did'
