Out of Curiosity

From what i've seen, every Private server with WOTLK Content/Server on it seems to be very popular than other Expansions.



Why is that?

And yes i know that WOTLK had so many Quality of life like Dual Spec, RDF and some other things but WHAT made it very good? Aside from what i said about the Quality of Life additions.
I can also think of Blizzard's Number 1 Posterboy The Lich King.
So,

Why is Wrath of the Lich King Expansion so loved by the Community?

I would say mainly because it is the most developed ''old wow'' expansion.
The last of its kind.

Probably because it is the expansion that strikes the sweet spot between catering for casuals and harcores