Is an environment card a villain target?
No.
I found the clarifications document here: http://www.spiffworld.com/sotm/files/sotm_rules_and_clarifications.pdf
It reads, in part:

What constitutes a Hero or Villain or Environment Target?
Any card with hp on it is a target, and the type of deck it came from determines
what kind of a target it is. for example, the “Enraged T-Rex” is an Environment
card since it comes from the Environment deck, and because it has hp, it is a
target. Therefore, it is an Environment Target. Same with a Villain card like
“Blade Battalion”; it is a villain card because it comes from the Villain deck, and
because it has hp, it is a target, so it’s a Villain Target. likewise, “Decoy
Projection” is a Hero card from a Hero deck which has hp, and so is a Hero
Target.

So Villainous Weaponry is an environment target, not a villain target.