Amid all the Salmond-is-Mussolini ravings, you'd have been forgiven for overlooking by far the most important revelation in the article -
"I was summoned to a meeting with STV’s head of digital and head of news and told my role was being changed. I could edit STV’s politics page or I could write but I could no longer do both."
In other words, Daisley was asked to make a perfectly reasonable choice. He could carry on as STV's digital politics editor and do it in the impartial way that would be expected of anyone else in such a position - or he could carry on writing his columns giving his own personal views. For reasons that mysteriously aren't specified, Daisley chose to give up his columns. So it turns out that all the stuff from Nick Cohen and chums about how Daisley was "silenced" is a load of guff - he was perfectly at liberty, if he so chose, to continue using the highly privileged platform he'd been given (one that for a long time was literally not afforded to anyone else at all) to express his political opinions on a high-profile and trusted website. Instead, he walked away.
A few cynics may be wondering what this whole drama has really been about, and whether Daisley seized upon an opportunity to pose as a unionist martyr in the interests of his own career. Seems to be paying off for him - I would imagine that his Mail column will be rather better remunerated than the STV gig.