I don't think hotspots can be said to have different composition. But if the hotspot is under a continent or an ocean plate makes a difference for the type of eruptions. Hawaii is in the middle of an ocean plate, no continental crust there. So we get a basaltic eruption (comparatively lower silica content, low viscosity lava).
Yellowstone is also caused by hotspot volcanism. The friendly eruption is a property of location, not hotspot origin.
Your initial post read the other way, which the parent post is addressing.
It's a brief and lighthearted explanation and trying to overgeneralize it doesn't make sense. There's always more details to it. Besides, there's plenty of shield volcano ("nice") events in the history of the Yellowstone hotspot.