That's a rather drastic generalization! As a counterpoint I've worked on professional teams with, what, 20 or 30 different Haskellers over the years and the number of "toxic, dramatic, dogmatic people" in that set is zero (or one if I really stretch the definition, and then only dogmatic, not toxic or dramatic). None were poor at their jobs, and the proportion of truly excellent software engineers with deep capability in the hard and soft skills needed to get code shipped was far greater than 50%.

That said, if toxic behavior occurs it can be more visible in smaller communities, just by how the numbers work out, so I don't doubt you've had a hard time interacting with some Haskellers, and I sympathize with you. Please point me to any toxic behavior you see in the public Haskell community and I'll do my best to address it with whatever authority I have.