I am glad they made more then 90 episodes . Thats a good life for any cartoon . I have seen plenty of toons that did not even make 20 episodes.
They quit because the public was losing interest in MOTU and POP . This was a business and profit yadda yadda reason . The writers also said they ran out of idea,s literally which i think is a lame excuse .
Bravestarr was the new kid on the block and they wanted to try their luck with him .
New Adventures came years later . Mattel just wanted to retry their luck on profits but i think it failed because of all the child friendly idea,s .