What if the rich kid scores 3As, the poor kid scores 7A1s but the poor kid cannot enter u but the rich kid can, because of quota system?

You have your point, but you are assuming only bumi students are poor and require quota to give them a leg up. Many non bumis are also too poor to enrol in private tertiary institutions if they can't enrol in public u.

Ask yourself: with quota in place, how many rural bumis still miss out on tertiary education? Using your reasoning (quota helps rural poor bumi), we should expect many rural poor bumi to be studying in university, kan? Is this the reality, especially among bumi orang Asli?

That's where scholarships and educational grants come in. You want to set a minimum standard for entry.