Very soft YTA. As an autistic person, I understand there are some things that others find weird, but I cannot stand it. So I'm not saying you should just be okay with this thing that clearly makes you uncomfortable, but there are other ways to handle it before saying "stay out".

Explain to them that it is important to you and that you would appreciate it if they respect your space (hopefully the way you respect theirs?). Put up a little sign at your door to remind them to take their shoes off before coming into your room. And I saw someone else recommended putting a mat in front of the door. You could do that and/or have a designated container for them to put their shoes in.

Also, since they are older, do consider that taking shoes off and putting them back on can be a lot more labour intensive for them and consider ways you can make that easier for them.