Not only that they use privative products - it's that people think about Krita as an alternative to Photoshop, as Krita is intended for digital painting rather than general raster image manipulation. Hence narrowing the target of Krita to a much smaller audience.
Assuming a product that advertises its lack of corporate support won’t be super welcoming of commercial users.
So they mostly only import (Krita-exported) PSD into Ps, or even if Krita was used professionally on the floor by employed artists, choice of tools would be up to artist's discretion and might not become a corporate talking point in the way, say, what Maya or Lightwave debate would be.
Maybe OnlyFans/Patreon could throw a million or two for couple years...? But Krita is not the first choice across the board, and creators on those platform don't seem too concerned with CSP/Procreate subscriptions, so that might be a difficult path too?
It won't. The only real workaround right now is to simultaneously launch SaaS alongside the FOSS project and monetize that heavily.
It can work. Paying for software is already a normal part of doing business, make this work to your advantage. For example:
- In the budgeting process just add a line item for the FOSS software you're using and put a number on it that's lower than the proprietary alternative. - If you're already using the software (like Krita in this case), tell whoever is in charge of the purse strings how much time, effort, and money the software has saved the company and ask them to make a one-off or recurring payment to the project that's lower than the alternative. You'll be surprised how often they say yes (as long as they can get a receipt)
Demand from the corporate entities proceed to dominate rather than voices from individual donations. Its a double edged sword.
It's hard for businesses hyperfocused on short-term gains to understand a long-term value of, for example, supporting an alternative for an industry-dominating Adobe toolkit. But the value is there.