Let's not forget DSA is still is a functioning regional airport with c 3/4 million passengers a year. That is not to be sneezed at ...
The aviation industry is only just starting to show glimmers of growth. European airlines are starting to order aircraft and open new routes for the first time in a major way for years.
Personally, I think DSA will have it's time? Why? Because:
1. It takes time. Look at STN, it sat there empty for years and years until it got its big break
2. Timing was pants, the economic cycle, logistical issues all played a part of capping growth in the short term at DSA. But we can take a more mid to long term view ...
However, I do think the problem is a chicken vs egg one. In my opinion DSA needs a core 'bread and butter' market that is not reliant on charters / leisure flights to underpin it. This is what keeps the place going in the 'leisure quiet' months (winter). The problem here is, although there is a sizeable population for which DSA is by far the most convenient airport, the economy is not quite at a level where it can sustain a more business focused operation (e.g., routes like AMS, BHD, CDG, and other key business centres).
Here is the chicken and egg - the economy won't attract the inward investment it needs without the connectivity, and the airlines won't stump up the routes without the market activity. So, in the short term without intervention, companies will continue to go to invest in Manchester, Leeds and beyond.
Now, if you ask me, if the local and regional councils really wanted to help DSA, they should be offering support to develop a useful network on flights that will support economic growth, then, and I think only then, will the South Yorkshire region attract the inward investment it so desperately needs, and start to address the unbalance of economic activity across that whole region. Let us not forget South Yorkshire is technically a deprived region ...
This was the case that was argued at the planning inquiry for Finningley as it then was, alas circumstances change and the airport made the investment but the external support was not there as much as it perhaps could have been. And here I have to say, the airport is 100% right about the link road. Without fast road access to Sheffield, the airport will always lose out to LBA and MAN. The bigger issue though, as I said above, is that without the link road, and some useful business routes at DSA, Sheffield city will continue to lose out Leeds, Manchester, Birmingham, Bristol etc as they just don't have the option to connect to international markets quickly and easy.
The argument for reopening Sheffield City is sweet but I think that ship has sailed. I was upset when SZD closed as I think location it was probably the best bet, but with a 1200m runway you're pushed to get a Q400 in, and so unless they can add 600m to the runway (which they can't) then I think it's a dream.
Make the most of DSA, and if the local, city and regional councils really want it to work, I don't think it's beyond the wit of man to make something happen ...