Let's not forget that back in the day QFF was far better and rewarding before the various enhancements, "simpler and unfairer" and all the rest where your MH and QR and all would give you decent earn. Those days are gone. BA can (and likely will) change many times. The grass is greener there, and in a few years maybe not. We each need to choose with short, medium and long term goals in mind IMO.
It makes sense being close to LTG to reach that goal - then that is a benefit locked in (hopefully for "life"!) then one is more free to expore other OW options - like BAEC. Plus travel patterns will also determine, to some extent, where one pools points. I mean for me I barely touch the UK, and think I last flew BA like 5 years ago (on an AY codeshare no less) so it wouldn't make much sense to me to pool to BAEC unless I changed my habits and flew them much more - as much as GGL and LTP equivalent seem enticing and maybe possible before I stop travel, it doesn't fit my travel profile right now. That's just me. The OP, and others, may be very different, and it makes sense.
Certainly the way QF/MH as noted by MH-Fan currently "works" is shameful specially for paid J (which I have done) and going to a program that would reward regular travel on MH, and other partners (like QR) where QF give less than stellar credit makes a LOT of sense. With the OWS afford by QFF LTG (how many TLA's can I fit in one sentence
) then looking elsewhere makes a LOT of sense!
My other strategy is to maintain status and earning in another major alliance. For me, it's Star and UA - as coughpy as they are I am near to lifetime *G status which - much like the OP's point about QFF LTG is a fallback target. Not only that, but there are far more earning, redemption options across both major alliances to make trips to just about anywhere be earners in one or both alliances. As example a few years ago I took a trip to far eastern Canada (the Maritimes) wherer the only service in is on either WS-with no QF codes or earn at the time, and AC). My trip woumnd up a mix of QF to the US, AA internal and AC from EWR into and out of Canada. That worked out very nicely for both my main earnings accounts. Or another trip I took awards in TG F to get to PRG via MUC and came back on AY/QF - again splitting the difference and making use of both.
Everyone has their own strategy and reasons for the choices - and only each of us can decide on the value - and also take the chance that the strategy we pick will work out the way we hope with ever changing programs
good luck to all!