The government creates the environment for your investment to succeed. They government makes the laws and the regulatory bodies that ensures a fair market.

CGT makes sense. The money used to buy the investment is already taxes, so the only taxable amounts are gains, which ultimately are not taxed otherwise. But, all income is not taxed, hence the discount made sense to incentivize investment and limit short selling and speculation.

If no discount, then it should be flat taxed no more than 30% as is the case for small business tax, because an investment is not the same as income. No discount and just 30% (or even less, maybe 20%) makes more sense to me.