On most occasions, 'people' is a plural noun in English and takes a plural verb. I use the word 'most' as there are some rare occasions when it has a singular sense but this is rarely used in day to day conversation. This is something that Spanish speakers really struggle with as they tend to directly translate 'la gente es'. 'People is' sounds horrible to native English speakers. Now, coming to your question, it's not a correct sentence. But my impression is that the person writing it may have simply made a typo and omitted the word 'it' as Is it the people who don't fit in who change the world? is a correct sentence. However, knowing the problems Spanish speakers have with this word, if a native Spanish-speaker had written it then it is more likely they have simply made a mistake. Not knowing the original source material I cannot say for sure. 'Are the people who don't the fit in the ones that change the world?' would be what I would have written using 'are.'

You're right, that sentence is not correct. I'd say that the correct form is: "Are the people who don't fit in those who can change the world?" hope this helps :)