It may depend on how far removed from the state the company is.
I would have to agree, as mentioned in the article, that it would be a bit odd if state owned/backed rail companies from other EU states could bid to run the ECML but on from the UK couldn't.
Living in Peterborough and using East Coast occasionally I have to say they've certainly made big improvements in staffing at Peterborough station. For one thing you can actually find station staff to ask questions and they even seem to be vaguely interested in helping people.