I think Earthspark's biggest flaw, in general, is that the Humans are the main characters. Like, I think if Earthspark followed the Terrans, and only sometimes Mo and Robby, the show could honestly be better.
Like with TFP, the humans are there. But its very clear the transformers are the main characters, not the humans. They aren't useless, and even though the humans do cause trouble, Miko i adore you, but looking at you, they can still handle themselves. They don't take over the plot very often.
Where else in Earthspark, most of, if not all problems, usually stem from Robby. I know Mo has also had her own issues, but she learns from them. Like, actually learns, unlike Robby who continously falls back.
I like Earthspark. I think concepts are fun. But after Season 4, man. I wish they did better with it. Earthspark introduced the concept of Terrans, Earthern Cybertronians, and they've done nothing wirh them. And it sucks. The Terrans are honestly such a cool and awesome concept, and the waste of them is sad to see. Like, I love Twitch so much.