Its not a conspiracy theory, the Khazar jewish empire that the Turks created lasted as long as the Ottoman empire. When the Cuman Turks destroyed it many fled across eastern europe.
Turkish tribes converted to Islam and for a thousand years became its prominent power, Turks converting to judaism would have a similar effect on that religion.
other Turkic tribes like the bulgers completely converted to Christianity. Turkic history is vast.
Are all jews Khazar descendents, nope but to suggest that none are is outlandish.