Quality is subjective. The value Nintendo was preserving with their cartridge licensing was the retail price. Too many low-cost games taking up shelf space in retail stores makes it harder to sell premium games. Games were sold for Nintendo consoles at remarkable prices, which encouraged studios to invest in high quality games. Chrono Trigger in 1995 was released for 11400yen (US$124.50 at the time).

But an app store doesn't have the limitation of inventory. No number of low-cost games will impair the ability to sell the premium titles. Not needing to worry about dilution, the store operator reverts to rent-seeking behavior and will approve the most number of games as they can. Or will create artificial scarcity by restricting access to popular titles.

When buying physical media, licensing balances the needs of the publisher, producer, and customer. But in the digital world there's almost no overlap.