Malaysia is actually very ready to became high income country. There's several factors that people don't want to talk about it, the reason why Malaysia trapped in middle income situation.
1. Malaysia have world most ethnic discrimination policy. Some Malaysia ethnic group is actually ready to lift Malaysia economy up to the next level. But the discrimination makes this high educated people to leave the country and created a massive brain drain, the world worst too. Actually, it's Singapore who get the benefit from it, as Singapore economy is booming right now from the high skilled workers from Malaysia.
2. Malaysia is also have a demographic problem too, where some ethnic group became more and more religious. Where the number of religious people now, hugely outnumbered the hardworking people. That makes their economy progress became a hostage because of it, as a small numbered hardworking people not enough to support entire nation, their income became stagnant. If Malaysia focus on hardworking culture rather than fall into a religion utopia, thing will be different.