a) you have never listened to Autopsy's Mental Funeral, Sempiternal Deathreign's The Spooky Gloom or Winter's Into Darkness.
b) you just think that playing slow = doom.
Doom metal of all sorts needs to incorporate a depressing and/or overwhelming atmosphere. All the bands like that had it, whether it would be the architectural work that Black Sabbath laid out, the 80's reign with Candlemass and Witchfinder General, and especially the funeral doom uprising established by Thergothon, Unholy, Shape of Despair, etc., even Katatonia's first two albums and the stuff Saturnus did had it. Swallow the Scum has none of that. Instead, you get some overproduced happy melodeath shit that sounds like a slowed down version of In Flames's Colony. It's sad that this is considered death doom. It's even sadder that the group come from Finland yet they ain't shit to the doom scene that was elite at the time.