Krita Foundation is a non-profit organization, but it is not a charity per se (so for example you cannot get tax deduction based on donations to KF). So if Amazon Smile doesn’t allow non-profits that are not charities, Krita cannot get register there.
Btw, reading about it, I’ve found this (https://org.amazon.com/ref=smi_ge2_ul_cc_cc?encoding=UTF8&%2AVersion%2A=1&%2Aentries%2A=0&ref=smi_chpf_redirect):
Will customers still be able to select my charitable organization if I don’t register?
Yes. As long as your organization is listed by GuideStar and meets our eligibility criteria, customers will be able to select your organization. However, no donations will be made to your organization until you complete your free registration. See “What happens if we do not register …” under Receive Donations for more information on how donations are processed for organizations that do not register and provide bank account information.
Damn… that sounds terrible: so the user thinks they are donating, but they’re in fact aren’t. Great.
I’ve read some more and confirmed Krita Foundation cannot participate (as far as I can tell… I guess @halla might be needed to confirm this for 100% sure):
What are the eligibility requirements for charitable organizations to participate?
Organizations must be registered and in good standing with the IRS as a 501©(3) to be eligible to participate. Organizations must be public charitable organizations (not private foundations) and may not be supporting organizations, unless identified specifically as a Type I, Type II, or functionally integrated Type III supporting organization. Eligible charitable organizations must also be located in one of the 50 U.S. states, the District of Columbia, American Samoa, the Commonwealth of Puerto Rico, the Commonwealth of the Northern Mariana Islands, Guam, or the U.S. Virgin Islands.
Krita Foundation is registered in The Netherlands and is, in fact, a private foundation, not a charity, as far as I can tell.
If you want to help with small amounts, we will hopefully have a good patreon-like program soon - something like Blender’s Development Fund, but for Krita. We already have one, but it’s a bit difficult to manage it, cancel, change amount etc., so this new project will hopefully make it easier.
EDIT Ok, I noticed this:
What happens if we do not register our charitable organization and provide a bank account for an electronic transfer?
If you have not registered and have donations allocated to your organization, we will attempt to contact you with instructions on how to register. If you do not register your charitable organization, including providing accurate bank account information for an electronic transfer, the AmazonSmile Foundation will still track and store donations earned in each calendar quarter. Once you’ve registered your charitable organization, your organization will be eligible to receive in the next donation cycle all donation amounts that were previously allocated to your organization and were not subject to reallocation under the Participation Agreement. Please note that donations that have been allocated to an unregistered charitable organization from customers that made their first supporting purchase more than eight full quarters ago and have not been distributed will be reallocated to other registered charitable organizations.
So they’re not absolutely terrible there; they do try to contact, or at least they claim to, and keep money for the organization. However it’s still Amazon and it’s still a terrible company (that’s my personal opinion, not opinion of Krita Foundation, who I cannot represent anyway )