Agreed, although I believe the early Gnostics were an intergral part of the tenets of early Christianity that got bumped out as time progressed...magritte
That is a common view, on that has been debated often in the last 30 years.
Academically, I am in the camp that sees them as separate, and pre-Christian groups that later adopted some tenants of Christianity in an attempt to integrate, rather than being considered Christian and then removed by a hierarchy.