F# is simply an ML variant. ML is fairly well-regarded among functional programmers as far as I know. I have not heard anybody who actually knows anything about the matter say F# is a particularly bad language.
The people who do say it is, however, are the kind of people who go on long, badly spelled, incoherent rants about how Microsoft is EVIL AND MUST BE STOPPED, which are full of errors and outright lies.
You were wrong.