Well, that escalated quickly!
In all seriousness, though, I can accept that to some degree, partsforming is a necessary evil when it comes to combiners. My problem is when the extra parts have nowhere to go outside of gestalt mode, or when they do have somewhere to go but it's impractical/ugly as hell.
An example of combiner kibble done well is the MMC Feral Rex/Not Predaking. The hands and feet are very well stored, the hand slotting into the foot which forms a kind of artillery piece/backpack that can be carried in vehicle and robot mode (and doesn't cause any problems when transforming either, unlike the FP Bruticus). Likewise, Hercules- his only combiner kibble is the hands and the chestplate, which both have somewhere to go in the individual modes (and the chestplate isn't really necessary for the combined mode anyway).
By the looks of things, though, the upcoming TFC not-Defensor, Prometheus, has add-on feet with nowhere to go in the individual modes. They don't seem to form extra accessories, they don't store anywhere, they don't transform into "drone" vehicles...they just sit off to the side with nothing to do. The TFC/Sirtoys not-Dinobots are even worse, relying heavily on combiner kibble, all of which is completely devoid of anywhere to go in the individual modes.
Now, it could be argued that these combiners need kibble to be accurate to the G1 combiners, but here's the thing; the G1 combiners were dreadful
. Practically no articulation and a metric tonne of combiner kibble- not just feet and hands, but chestplates, weapons, heads, and all sorts- with literally no uses beyond being parts of the combined mode. And the individual robots were hardly great either, with typical brick-level articulation and somewhat crummy designs.
Of course, we can forgive these flaws, as it was the 80s and toy technology was far more limited. But why would we want to emulate the flaws these toys had when we have the technology to make much, much better figures? You can still homage the characters and concepts without slavishly obeying every single detail, including the crap bits.
Of course, there is the perfectly valid point that integrating the parts makes the individual robots worse. But the thing is, with modern engineering (and the kind of budgets 3rd party toymakers have for these things) that needn't be a problem. Feet would be very easy to integrate into the individual members of the team- all you actually need for feet are flat surfaces with a little bit of tilt. Not exactly difficult to engineer- you could very easily just form a foot from the front half of the leg-bot's vehicle mode. Hands would be more difficult to integrate, yes, but it has been done- FoC Vortex managed to do it, and his robot mode was plenty decent. In fact, its shortcomings arose from having to form an arm or a leg and budget restraints- the hand could have easily been made articulated for starters, and with a little work I'm sure the ankle tilts that everybody loves so much could have been worked in to the robot mode. And like I say, why would a combiner need normal hands? Wouldn't claws or built-in weapons make more sense? Like I say, some partsforming is necessary, but I think a lot of times, the designers of these things just go "You know, we could easily get this bit to form a useful part of the individual robot, but let's just make it a separate piece of junk in the non-combined mode, that's much easier".
The Energon combiners, in my opinion, got it right- the hands and feet were separate pieces, yes, but they just formed the weapons of the individual robots, and were the only parts requiring partsforming. And on top of that, they functioned as the combined form's weapons as well- forming giant claws, cannons and gun assemblies. Sure they could have been better (it would have been nice if there were 4 different limb-bots per combiner) but at the end of the day, they had to be made on a budget for the mass market, with all the pitfalls and safety standards that come with that, and factoring that in, they were pretty good.
The other thing that annoys me about partsforming is that it kind of detracts from what a combiner is supposed to be- a huge robot made from multiple smaller robots. To me at least, the charm of combiners is that they are formed entirely from the individual robots. When 50% of the combined robot form is extra junk it seems less like a combiner and more like a normal humongous mecha that just so happens to have some smaller robots inside him. The FansProject Menasor is particularly guilty of this IMO- the legs aren't even formed from the limb-bots, they're just not-Motormaster's legs extended and with cars stuck on them, which defeats the purpose of him being a combiner entirely.
Eh, I dunno. I just wish someone would at least try to make a combiner with the parts properly integrated. I'm absolutely sure it can be done, and done well (without compromising the individual modes) I just think someone needs to try it.