The difference is that the employees at tier 1 backbone providers get paid, and if one of them quits, there is an organization responsible (and incentivized) to hire and train replacements.
So what? That doesn't make those people, the software they write, or the actions they take any less important at keeping the internet functioning. The work employees do seem to constantly be downplayed since they often are not working out in the public, nor are they making public blog posts advertising what they are doing.
Never make OSS your full time job unless the company employing you pays you for it.
OSS is a strategy, not a business model, and it is certainly not a good lifestyle for developers.