Hero Factory was interesting to me when I read some of the comics that came out in the Lego Magazine. However, when they stopped focusing on the awesome comics, background stories, and designs... I grew to have distaste in it.
I hate it when they try to dumb things down for little kids. Sure, when I was younger, I hardly understood much of BIONICLE's story, but I had a brother who did, and he told me about how things went on. BIONICLE became fascinating to me with all the locations, objects, and characters. I became convinced there was another world out there. And it made me understand and marvel at these characters... When I was only 6 years old!
Hero factory is missing those factors. They only care about heroes fighting villains, which made me wonder: What was the villain's motives besides wanting revenge and power? Couldn't they add more to the whole "revenge" thing?
BIONICLE's storyline with the Makuta had this factor. The Makuta misunderstood the meaning of duty, and became jealous of Mata Nui because he received all the praise. Eventually, he got revenge, but Teridax betrayed his other brethren by letting them get killed in a shockwave, and then took over the universe, full of innocent Matoran. Now that is just pure evil right there.
What did hero factory do? "I want revenge on Stormer! I want revenge of Hero Factory!" Now, this could be reasonable for one villain, but several? It makes you wonder how many of Stormer's and Hero Factory's allies and enemies had something bad happen because of them? This reasoning is cliche and overall is not a clever way to introduce a villain's origin.
If they payed attention to BIONICLE's critical success, perhaps Hero Factory could have become something grand.