Of course one can have a deep distrust of the government without believing it’s run by lizard people from another planet.
Put another way without specific example or analogy: if there is some organization as large as a nation's government (thousands upon thousands of organizations, possibly millions of people) and you can't weigh things done by said government without always invoking a single nefarious/secretive plot or group being behind it every time then you've left the realm of standard or reasonable distrust and entered the realm of unfalsifiable, unhinged thinking the article is meaning by deep distrust. Even the worst governments in our world's history aren't reasonably measured that way. The alternative to this is not blind trust, it's normal distrust GP was arguing for.
That being said, you still haven’t convinced me. I claim I t’s very possible to hold deep distrust without attributing intentions/motivations to conspiratorial actions.
The act of distrusting does not require an assumption of motivations (or a nefarious/secretive plot, as you put it).
I think we both agree distrust doesn't require a universal underlying motivation but you're continuing to use "distrust" and "deep distrust" interchangeably without explaining why people should consider them interchangeable in context of the article.
One may distrust their state, but in some regards can still trust. One with deep distrust will likely never trust, their level of distrust is much higher. This does not require a conspiratorial mindset.