Haven't read any of this thread but here's my take on it:
Deila inherited a pile of s**te from Neil "cannae get a job" Lennon. Lennon recognised he'd signed a load of duds (with one or two exceptions but they pale into insignificance compared to the s**te that is Pukki, Balde et al) and knew the Board wasn't going to give him any more cash to blow so he f**ed off. We're now suffering the consequences of Lennon's failure to sign decent players.
The fault doesn't lie at Deila's door. It lies with the Board and, to a lesser extent, Neil Lennon. We're a pretty poor team with a Board unwilling to invest money and the choice of manager reflects that. Deila was the cheap choice. The Board chose him because they wanted someone who would work on a shoestring budget. People need to accept that but the club also needs to understand that people shouldn't be charged hundreds of pounds to buy season tickets for a team that would struggle in the English Championship.
I hate to be pessimistic but Scottish football is at death's door. The decline has been going on since Seville. Okay, there's been a few highs since then such as Celtic reaching the last 16 of the CL and Rangers reaching the UEFA Cup final but the general trend has been a downwards spiral for the Scottish game. Unless something radical happens over the next five years we're in danger of disappearing off the European radar in the same way Hungarian teams did during the 1970s (and have never recovered).