Do you really only see the two options of having "hyperspecialized" planets and having "generalist planets"? If so, you should perhaps take a step back from arguing and consider all the middle ground that exists between the two extremes, before you dismiss all of it because you only looked at the extreme. Nowhere did I say that every planet should produce all resources, and the new system in no way suggests that every planet should do that either. If it did, that'd be just as boring as hyperspecializing everything.
Ideally, I'd want specialized planets to be the baseline, but then there should be incentives that make you consider whether maybe it's worth producing some resources directly on the planet as well. If your Forge planet has a bonus modifier to mineral production, why not have some mining districts to make it fuel its own industry? Or if you need some food, but not enough to build a fully specialized Agriworld yet, why not place it on a planet that's currently in a deficit instead of stacking them all in one place?
You can either specialize your planets, or have them produce a bit of everything but do nothing well. There's no "middle ground" for this. At best it's a gradient but at the end of the day they'll very much be somewhere on it and trending towards one of these two. And since generalist planets are inefficient you need outright punishment and heavy handed developer influence to force anyone who halfway understands the economy to use them.
Hell, even the people who proclaim to love them aren't using them. And that's for a reason. You could use them right now. But that's not enough. They need to be forced, at gun point. Lowest common denominator.
"why not place it on a planet that's currently in a deficit".
Because that's a terrible approach. Not only is that planet already producing something, and has a focus on it. You would need to build up an entire second infrastructure on that planet including the bonuses. Then you'd have to massively shift workers away from what the planet is currently producing all to produce a small amount of food and solve a problem short term. Rather than create a proper long term solution with future growth.
Ignoring that the workers to work those jobs don't magically come out of nowhere. You're taking them out of jobs currently being worked, while also reducing the growth of the planets main production over time as those new workers generated are now split between these two.
Honestly, this approach is so incredibly flawed and has so many issues on so many levels. It entirely misses the problems at hand, it ignores that you can have at most three zones in the new system, that work force is usually a limiting factor, that you'd have to retool what the planet is currently doing to create inferior production and hurt yourself long term, all to create a stopgap solution.
Sometimes talking to people on this forum makes me wonder if they're actually playing this game. And if so, at which difficulty and to what year. Because some of the things people come up with makes it seem as if folks lose interest super early into the game.
Darth -Marauder-, because only a Sith thinks in nothing but extremes
Do you mean "Only Sith deal in absolutes"? Which is itself an absolute statement. Not an argument though.