I cant because what other business does this?
Disney: Want to see Avengers: Endgame in theaters? Well we might release it if you buy the 4K Blu-Ray of Mary Poppins Returns.
If you think other business don't do this practice then you're sadly mistaken. It's just many businesses dont say it like how Capcom says it because clearly you can tell it sounds stupid and will just receive a lot of backlash.
One thought could be that Capcom has a set budget for each console so for Capcom to produce more for Switch they rely on making more money from Switch which is why they require DD to sell well on Switch? But that's just a thought (of many), who knows how their business is run or what the shareholders want. Only way to truly know is to be at their boardroom meetings lol