Well, to be fair, it has never been confirmed the Reachmen actually worship the Daedra, it's just rumors. And if we wanna go by the rumors, they worship Daedra such as Azura and Hircine, which are probably some of the most ''morally-good'' Daedras out there. Regardless, I don't see how their actions are in anyway justificable. Maybe the lands were their property before, but they were driven out, they were beaten fair and square and they lost the territory. It's simple as that. It isn't right to act like wild savages and murder innocent people, some people who probably didn't even have anything to do with the rebellion against the Reachmen in the first place. The Forsworn's alignment is pretty much Chaotic Evil as far as I'm concerned.
You're replies are entertaining, I'll admit.
The Reachmen, also known as the Witchmen of High Rock, are a tribal group of primarilyBreton descent who inhabit the Reach in southwestern Skyrim[1] and the neighboringWestern Reach in the east of High Rock.[2] Their ancestry includes not only Bretons, but spreads across many of the known races of Tamriel.[2] They mainly utilize primitive gear and hedge-magic, have a tribal appearance and nature, and typically inhabit makeshift fortresses built into caves and ruins throughout the Reach's battle-scarred landscape.[1][2] They primarily worship Hircine, the most primal of the Daedric Princes, although some clans are said to also dedicate ceremonies to Molag Bal, Malacath, Mehrunes Dagon and Namira.[3][4] Their shamans venerated the Hagraven "matrons", who in turn granted them knowledge of nature magic.[5]
Uesp Wiki
Need I say anymore?