In general terms, if there's a policy decision that's taken by a government, it can get complex, I think, but it's always possible to draft your way there. In this case, the government decided to maintain the tax on split income level at 33% to maintain the disincentive to splitting income.
To answer what I think you'd also asked about, ways to avoid the tax on split income, it's worth keeping in mind that the simplest way to avoid the rules is that if you have family members involved in the business, pay them salary instead of dividends. In that case, you're not even in the realm of the tax on split income, you're just under the general rules for salary. Many business owners, in particular when they have minors or people under the age of 18 involved in the business, will simply pay a salary.