You keep talking about deserved but there is no deserved about it, its like asking if the rabbit deserves to be eaten by the wolf, if you are not under the aegis of Satan's protection then you cannot expect His protection, no the Gods cannot save literally every soul as the enemy is not weak or powerless in this regard especially when the vast majority of souls damn themselves, frankly Satan and the Gods are extremely generous in how many of those who are without they protect in the afterlife, afterall every christian and muslim has made it their lives mission to disrespect our Lord and still he shows them mercy and kindness.
As for the afterlife the dedicated of Satan are guaranteed to make it to the resting place of the afterlife, and then depending on their actions in life they will be treated accordingly, for many of us it will be a very pleasant experience for those who are without however the higher levels of the astral are simply something they cannot exist within, yes the Gods still take their souls but there is no guarantee for them or theirs unlike with us who are guaranteed a place, furthermore the afterlife even is a big place, and the experience of Duat varies wildly depending on the individual soul, but dedicated Satanists are treated extremely well.
And frankly many of those who are damned do in fact deserve it, they certainly earned it either way the systems of the enemy are willfully evil and their followers are ignorant at best and outright evil at worst, what sort of place do the ignorant and the evil expect? Satan gives more than any of us understand, expecting more is frankly entitlement.