Great post mate. I think the thing is that Ross was only an example. There were many correct reasons why he wouldn't have been interested at the time and it's no real shock he gave us the runaround.
I think, for me, most of what you've described has been because of the poor managerial appointments we've made, rather than because we're some sort of basket case club. Realistically any appointment is fraught with risk, but from Barry Smith (no experience and an appointment made out of necessity) to Bomber (just a bizarre move), through Hartley (arguably the only one of the recent appointments that felt properly thought through) to McCann (did anyone say bizarre?) to the panic stations and about turn of McIntyre to the (being really harsh here) budget option of the extremely respected novice of McPake it just feels like we constantly make do and compromise purely because the folk appointing these guys simply have no connections within the game.
As you say, that leaves a dearth of knowledge above the manager to guide, advise and, at times, say no to the manager, which arguably has caused the majority of the problems that have ensued. However, I'd argue that what's really been lacking is coaching ability - the experience and vision to shape a team with a solid core and clear plan that can, mostly, dictate play and impose their style on the opposition. What constantly appointing rookies (including Bomber, who kinda was and kinda wasn't, so three of the last five have been given their first go at Dens and then done basically nothing since) has resulted in is the exact opposite. It really feels like McCann and McPake are working from a manual - constantly shuffling and changing to mitigate so-so opposition and imposing an admirable style often beyond the players at their disposal.
So far, on paper, McPake's recruitment is much more steady (McCann got a few really right and most REALLY wrong) but I can't help but feel that a more experienced manager (being honest, I can't suggest any as I really don't have much of an interest beyond DFC these days) could have shaped the players in a much more effective way.
There are arguments on both sides but - taking away McIntyre who was just unbelievably out of his depth in an already admittedly bad situation - the constant rookie recruitment has dug us deeper and deeper into the hole McPake inherited and isn't quite getting us out of, yet. Although you only have to look down the road to Perth to see that rookies (Sturrock, McInnes, Wright) can work out at a more stable club with much more clear constraints and budgets.
The part where I maybe move away from your point of view is that if you offered someone with a bit of experience and a reputation the backing that Hartley, or McCann received in budget and time to get it right (or wrong), while being at the helm of a club that genuinely has the potential to regularly compete for mid-table in the top division, then, arguably, what better jobs are there in Scotland for a manager at that level? Either way, the more we analyse it, the harder it becomes not to come to the conclusion that the real problem lies higher up than the manager's position.