When I see players currently making a go of it in the Prem, who are subject to interest from the biggest teams in England - Scott Sinclair, Victor Moses for example - I see a different standard of player to Adomah. At the moment Adomah is in transitional phase. The astonishing runs that brought him adulation and attention aren't deemed particularly necessary by Del - everything has a time and a place, after-all. So his passing is trying to be improved, his final ball, his positioning (the latter seems a struggle as he drifts into the middle at somewhat inopportune moments), the things it takes to go up a level.
Maybe he isn't enjoying this transition. Perhaps he worries that this hard-work is putting back a big move elsewhere. It probably is, but for him it'll be beneficial in the long-term - wherever he goes. I truly believe if he goes either now or in January, he'll be back in the Championship in some capacity the season after. I'm not saying he'll never make it, I just doubt he'll have the career he could have had if he were to have stayed.