First, a disclaimer, I have not finished the last podcast yet, so sorry if I leave anything important out.
I honestly don't care about the "height-difference" per-say, but I am against the Matoran having the extra-short mini-legs, not because of articulation, but because it makes them appear too small and helpless.
This is actually something that always irritated me in G1. Matoran were basically hopeless 90% of the time without the Toa. When it came to physical attributes, they were like children the Toa had to constantly save. Giving them the mini-legs which Lego uses for actual children would just make this problem worse.
I understand that long-term the Toa are the heroes who will be saving the day, but the Toa aren't around all the time (of even most of the time) so the Matoran must have some respectable ability to take care of themselves without them.
As far as I can tell, this is why TTV is giving them minor elemental powers and loosening up on the mask-power restrictions.
I would like to point out that the only reason Dwarves and Hobbits are taken seriously in the Lord of the Rings, is because the story is told from the Hobbit's perspective, and therefore all of these characters are "eye-level" with the audience. In LOTR, Hobbits are the actual human analog; "men" are treated as another fantasy race.
In this story, we are trying to make the Matoran the "human" analogs. The story is told from the Toa's perspective, but the Toa are clearly meant to be exceptional characters, in the same way in which Bilbo and Frodo's aging cycles were exceptional among hobbits, and you cannot illustrate that something is exceptional until you have established the base-line, which in Lego will always be defined by the classic Mini-Fig.
I agree that is a necessary plot element. The problem is that Mini-Legs are usually used as short-hand by Lego for children, so we won't be making that visually clear.
(And just for the record)
(Yes, the Greek gods were portrayed as extremely relatable. He got angry when people slighted him, he became sad/stressed when his children bickered, he worried about pleasing his wife, etc.)