do look more unstable and i would also suggest closure being the best option...
I dont think you can use that as a generic measure for financial viability to be honest. Some may well make more money being turned into industrial estates or housing, while others cant be developed as such. Some of them have other aviation revenue than just offering passenger flights.
I do think he was wrong to talk freely about his thoughts, the shareholders wont be happy!! Not to mention any talks that may be ongoing to attract new business to these sites could be hampered by it.
I can see the for sale sign gong up at BOH and HUY, with MAG wanting to get their hands on STN and either GLA or EDI. I have heard they would even sell EMA if it meant they were guaranteed to get their hands on STN!