Hi u/cdank, interesting question.

Generally speaking, IFS is right for a very wide spectrum of people.

I'd say it's not right for someone whose intention with IFS is to force change or healing inside themselves. Because this would mean abusing the powerful tool of IFS.

At least, it's not right for someone who's blended with a Self-Like Part that's determined to force change. But an experienced IFS therapist would be able to see that person is blended with a part and help them unblend so they can approach IFS with an attitude of true healing.

You can learn about how to unblend from Self-Like Parts like these in my free workshop next week: https://seekdeeply.com/workshop-ifs-therapy/

Aside from that, if someone really doesn't resonate with IFS, it might not be the right modality for them. (Sure, we could say that's a part feeling that way, but that doesn't mean the part's wrong.)

It's all about trusting yourself. Asking: What does my inner compass say?