I can appreciate why you'd come to this conclusion, but may I offer one idea that I think you've potentially overlooked?

Unless you are a solo founder running your own company by yourself (in which case ignore the rest of this comment!), then your fundamental job security is likely to be predicated on the survival of your company as well as the survival of your own individual job itself.

From the company-survival POV, all companies are engaged in competition (unless they have a total monopoly).

Therefore I ask you to consider the competitive scenario, of whether a competitor to your company who adopts a more collaborative culture, might be more likely to outcompete your company (assuming everyone you work with in your own company adopts a similarly "dick"-ish stance, to use your own words), and therefore you lose your job due to being out-competed, rather than due to internal politics or due to a failure to guard your personal expertise?

Maybe you say -- I don't care if my company is out-competed, I'll just get another job. Ok fair enough, but might it not be possible that, in a future job interview, they may ask you for examples of collaboration? And if you commit to a monk-like devotion to solitude and privacy, then maybe you are undercutting your own future hireability?

There are no free lunches [1]. By optimizing for one thing (what you view as protecting yourself), you might be sabotaging another dimension (your company's overall competitiveness, or your future hireability).

Anyway, nobody knows shit about shit. I certainly don't pretend to be an authority, but I would caution you to avoid coming to a hasty conclusion, especially since it seems emotions are involved and possibly clouding your judgement. You may also consider whether this decision to protect yourself in this way, is in itself a premature (micro?) optimization of a sort, and if whether you might be failing to optimize on a more macro level.

[1] https://en.wikipedia.org/wiki/No_such_thing_as_a_free_lunch