Again, no. That's not how the alignment system works. The books are VERY clear that neutrality is one of THREE things.
FIRST: Behavior that's not especially good or evil because it's not especially much of anything. That, I agree, not an adventurer's trademark. It's neutral, certainly, but the apathetic variety. We can dismiss that as very very boring. And thus not worth playing.
SECOND: Actions that go across the board. Sometimes being selfish, sometimes being selfless. Sometimes following the rules. Sometimes breaking them. The example I gave of House is a good one. MANY adventurers can fit here- I mean, played "as is" without at least minor "house settings", you *are* playing a team of disorganized but efficient murder-hobos.
By *definition* your typical D&D party travels from land to land, rarely having a specific mortal agency to which they lay fealty. Sure, they may have some god(s)... but still. They typically follow a more or less informally democratic process within the ranks- they have a leader, but only due to popular support. This is chaotic behavior. But they generally fight in favor of protecting the land from other, usually chaotic, forces. Supporting the local infrastructure and lords is lawful. So they come to a nice neutral zone.
There's rarely a specific rhyme or reason in this group working together- it's often a matter of convenience or a sense of shared goals. The group rarely shares an alignment, and if they do it's probably "good". And almost all of them tolerate a degree of independence and insubordination that would result in a court martial if tried by a member of any legitimate special forces team. But, still, they protect one another and form senses of obligation and trust with one another. One more chaotic act balanced by one more lawful act.
They may traverse the land aiding the vulnerable against the forces of evil. But they also have every intent to keep the lich-king's vast riches. And for every paladin chasing a holy cause, there's two thrillseekers hunting for new adventures or challenges to test their skills and FIVE mercenaries looking for a huge payday.
As such- True Neutral is almost an inherent default to any adventurer's activities. Though the individual goals of the party members define their own scale on the axis, the fact of the matter is that the group's overall default is almost always TN with an angling toward 'good' that doesn't actually reach the finish line.
THIRD: A true dedication, spiritually, to the concept of balance. This, of course, is the hardest one to adhere to. This is a druid following a razor's edge interpretation of the natural world. And in truth, this is the one that actually roleplaying is the hardest to do correctly. But, seriously, we got Lawful Stupid. We got Chaotic Stupid. We got Evil Stupid. Why can't there be Neutral Stupid?
The first is a lack of Desire. The second is a lack of Preference. The third is a Dedication to a peculiar ideal. Or, to put this in other terms, some people are Asexual, some people are Bisexual, and some people are Pansexual (or at least a good sized sample of them- I'm sure there's a few naturally pansexual people out there, though I've never actually MET one- everyone I've known who called themselves such actually put *effort* into it).
And then there's a question of intent vs practice. That's an issue and a half unto itself.