Nobody sets an arbitrary percentage of anything and forces dividends.
When the companies directors think that there is enough spare money in the bank account, generated from profits, they distribute those profits to the people who own the company.
The founders and investors of the company get the actual profits that the company generates. A strange concept I know!
Second, many companies, especially tech companies, do not pay dividends.
In particular, a growing company would be foolish to distribute dividends; dividends are for companies that have reached a steady-state. Waiting for a company to hit steady-state from inception can take a very long time.
My interpretation is that indie.vc is trying to change that from being status quo. There is a largely forgotten type of business that is not covered in tech media, which is highly profitable and pays dividends.