Perhaps a better analogy would be that asking "Why not pen testing?" is like asking why gun designers don't find new jobs as infantry.
Established security firms often focus on business with... guess who? Governments. The NSA employing people directly is not really much different from the NSA hiring contractors who employ people directly.
Not entirely. It starts as that, yes, because the first thing you do when attempting to break into a house is check the front door. There are obviously levels beyond this.
> is like asking why gun designers don't find new jobs as infantry.
But it's not entirely like that. There's plenty of firms that hire out security specialists to do code reviews for internal applications. At that point, it's like a gun designing consulting for manufacturing firmson ways to make their products more resistant to small arms. The job won't be the same, but there will be commonalities and the prior experience will transfer over usefully.
And your job is probably a lot less reliable, because short-term auditing or pen-testing contracts offer a lot less stability than 3-5 year government contracts.
"Help, I love designing guns, but the only people willing to pay me for that will use them for evil!"
If you're a talented "network attack specialist" then you're likely also a worthwhile network engineer. So work in that role and do the gun-design in your spare time and hopefully for a good cause.
Also, the skills required to be an effective network attack specialist have very little relation to those required to be a network engineer. I thought I covered this up-thread.
If you have a family to support then how about choosing a less problematic career path than "Network Attack Specialist"?
You are not entitled to making a living from your favorite hobby if that entails building a dystopian future for everyone.
This is ultimately a deeply personal choice that everyone has to make, but sometimes we really can't both have our cake and eat it too.
I also work at a government sponsored R&D lab, so I'm familiar with the conundrum (not for myself - I'm just a dumbass programmer whose skills are so pitifully generic I could go literally anywhere in the world... some of my colleagues - not so much)
Much closer would be writing boot loaders and compilers.