Sure there is. An (apparently) peaceful person from a friendly country was banned simply because she led an Internet signature campaign against a clandestine and borderline-rogue surveillance agency. How many other HNers would have signed a similar petition?
> Prior criminal convictions, affiliation with unsuitable political parties or organizations or poor character are valid justifications for denying entry according to US law
I don't see any of those being applicable in this case, at least as per the article.
When intelligent, well-informed and progressive citizens reach the point that they don't see anything wrong in a government/regime trying to muzzle critics, simply because they can and they have done so in the past, we implicitly grant approval to the continuation of such tactics.
The first step towards solving a problem is acknowledging you have one.