Can't say I think this is a bad decision. Many people use MS Paint for pixel art but that's largely because they started with it and got comfortable. These are pretty much the only people that this change will impact negatively.
I honestly think it's better for pixel artists to use more specialized programs. Now I can't say for sure (I don't do it myself), but it's like if someone got really comfortable with writing code in Notepad. Sure, you're used to it and it's already installed, but using a proper code editor is just better in a myriad of ways. The correlation isn't quite 1:1, but my point stands.
Besides, people can still use it if they insist on it. Later versions of Windows won't have it but there's nothing to stop you from getting it from previous versions, there are downloads online.
I honestly think it's better for pixel artists to use more specialized programs. Now I can't say for sure (I don't do it myself), but it's like if someone got really comfortable with writing code in Notepad. Sure, you're used to it and it's already installed, but using a proper code editor is just better in a myriad of ways. The correlation isn't quite 1:1, but my point stands.
Besides, people can still use it if they insist on it. Later versions of Windows won't have it but there's nothing to stop you from getting it from previous versions, there are downloads online.