From reading the article, it seems to me that the big challenge in laying terrorism charges is cost vs. benefit. If you can get the perpetrator locked up for 25 plus years on the criminal charges, and you aren't going to get anything more by getting a terrorism conviction too, then why waste the resources.

Perhaps a better option for the Quebec and Alberta persons mentioned in the article is dangerous offender status.  That could get an "eligible for parole in 25" converted to a "life with no chance of parole."