Jake's Theory
In the end, Jake stayed only a few hours in Hade's workshop. Soon the harsh realities of his physiology set in.
To mass produce Adamantium and other magical metals, he needed to eat a lot. A LOT.
If that was the only constraint he could have had it delivered to him, but his past mistakes had taught him a lesson. This time there was no way he was going to sabotage the future growth of his Bloodline.
To evolve optimally, his Gold Myrtharian Bloodline needed a 'balanced' diet. Lightning, heat, radiation, magnetism, gravity, earth and metal with the greatest possible diversity and in equal energetic proportions.
To be entirely fair, no place on Quanoth could provide such an environment in ideal proportions. In the meantime, he had to make do with his underground base and the Purgatory to get what he needed.