Having half the guys around you laid off [or about to be] is not what I would call "ticking along comfortably".
Twitter is not a 100 000 people company where there's a 300 people division being restructured. It's a major management failure that needs at least 50% of lay off. At this scale, it will reflect to the entire environment and all the employees.
As the article implies, it isn't far from profitability, and is cutting back to ensure it will be profitable.
Silicon Valley demands hockey-stick growth, but there's no reason why Twitter can't keep ticking along comfortably.