I do somewhat agree with this sentiment; after all the Prophet Muhammad (PBUH) was not either a Sunni or a Shiite or a Sufi or a Salafist. However, people express their devoutness in different ways as Muhammad (PBUH) hasn't been in this world for a millenia or so so it's quite hard to pin down "the right Islam" because it's almost entirely subjective. Definitely do respect this kind of mentality, though.
I don't think there are enough differences to warrant entire sects, following the Sunnah and a little common sense is all thats needed.