(Be careful with Pandora's box.)
Exactly.
My only point being that what this guy did was no less crazy or morally reprehensible - neither action is legitimate (unless you're predisposed to feel sympathy for the aggressor). The 67 year old IRS agent he selfishly killed
was an innocent bystander just as much as all those people in the WTC or the Pentagon; He just worked at the wrong place.
That's why no one but radical right-wing tea-party members are even giving a shit about this clown. He may have been bright (although he failed out of college and obviously sucked at finance and paperwork) and he may have felt justified but Timmothy McVeigh also falls into both those categories.
As for Guy Fawkes, apart from Moore's modern usage of the mask, the associations with him throughout history have been purely negative. He wasn't viewed as a freedom fighter, but rather a bit of a religious fanatic. Guy Fawkes night isn't a celebration of the plot, but rather the failure of the plot (hence the effigies of Fawkes being burnt). Likewise, the term "Guy" wasn't a good thing, but rather associated with Fawkes fucked up face in the effigies.
Back on topic, I agree with you that this guy probably had a point, but Que said it best; "And while I certainly can't condone his actions, I can understand the frustration". That can be said about a lot of people who do very bad things. Half of being a nut-job is escalation, and this guy falls into this category.