Why did Rayman Origins scrap it's original concept

It actually had Dialogue back then

Mr Dark would return, though as a Teensie

unused dialogue of the game's original plot

Magician, he had way more lore, not just stealing the fairies, but an actual plan to take over the world and give it order because of his hatred towards the bubble dreamers nightmares

Throughout the game the Magician pretends that he is still a friend of the heroes, he collects Lums from them in exchange for Electoons which they use to reach new areas.

"So, I hid a microphone in the tree to start a war! I took all your Lums to power my magnificent machines...Plus... I stunk at magic school... boo hoo hoo... the other kids teased me and tried out new tricks on me..."

Also

Raymans propellor ability

Health bar