I don't think they are heroes. I don't stand or applaud when vets are announced at sporting events I attend. But the other extreme, casting them as remorseless, calculated murderers is downright offensive. Walk in their shoes and then you can cast judgement. Ever been shot at? Ever been threatened with a courtmartial? Probably not.
While I agree that they are neither necessarily heroes, nor are they necessarily embodiments of evil--they are individuals, and some of them may very well be heroes, or evil doers, regardless of their military service--I don't think walking in one's shoes is necessary to cast judgment. I don't need to murder someone to know that murder is wrong, or to call murderers murderers. But, just to reiterate, I don't find guilt by association valid in this case.
As an aside, Ron Paul served in the military.
Ironically--ironic because I am agnostic--I generally have a mindset of 'forgive them, for they know not what they do' (Luke 23:34 IIRC) when it comes to the State's employees--be they military, police, or what have you--until they individually take action that is morally reprehensible. It is their individual actions that determine what wrong they have done, not simply their military or police service. Unfortunately, for military and police, if not others, they tend to corner themselves in a no-win situation where they have to support violence, or initiate violence themselves against otherwise innocent people, or else they too will become victims. While there has been conscription in the past, I suspect it is true for most today that no one made them join the police, or military--so in that sense, there was a choice. But again, where simply joining is concerned, 'forgive them, for they know not what they do.'
The vast majority of people believe they are serving good, and fighting evil. The vast majoirty of people join the police force, or the military because they believe it is honorable, and in the service of virtue.
In any case, playing these kinds of blame games for nothing more than association is ultimately a distraction. The true enemy is the State, and it's best not to lose sight of that.