I haven't seen anyone praising soulstorm as a game (while dark crusade gets a lot more good memories from the players) but it seems the praise is for the mods of soulstorm that are mostly recognized as the best in the dow series (mostly the Apocalypse and Unification mods) .
Soulstorm was fine as a game, iirc... not particularly
better than dark crusade, but not meaningfully worse, either. Which admittedly is something of a let down for a sequel, but it's not like it's unenjoyable as a base game experience.
... that said, yeah, you mod the hell out of soulstorm because the mods for soulstorm are pretty much the peak of DoW modding. All sorts of neat stuff going on on that front, probably unambiguously a better reason to get the game than the base game itself.