One of the major benefits of Open Source is that the user doesn't need to get a hold of the developer. It's always possible (or should be, if they're leveraging open source well) to patch a problem locally and build a fixed version their self. If they don't have the ability to do so, they really should at least have someone they can contact and pay (probably an exorbitant amount if it's an emergency) to do that for them. It's the open source equivalent of an application support contract or warranty.
If you've got a business that requires Firefox as some component (in a way that isn't easily swapped out for some other browser), you really should have someone on staff or available that knows how to build and change stuff in it. That said, it's odd for Firefox to be used this way, to my knowledge, which is nice because it's on the short list of open source projects that are so large and complex that depending on the problem your only recourse is likely outsourcing help. In other words, if Firefox is integral to your business, befriend and get some consultancy retainers from some Firefox devs if you don't have one on staff. Not doing so is probably irresponsible from a business perspective.
> If you've got a business that requires Firefox as some component (in a way that isn't easily swapped out for some other browser), you really should have someone on staff or available that knows how to build and change stuff in it.
That's incredibly excessive. If a website design agency runs Wordpress on Linux servers, that certainly doesn't justify having a kernel developer on staff.
Linux wouldn't be integral to their business. They could also easily run wordpress on BSD, or a Solaris derivative (Illumos), or Windows. Either Apache or Nginx specifically also wouldn't be integral, as they could use one or the other, or some other web server that works with PHP. PHP is integral to their business, but they're not using any special feature of it that others aren't, most likely (and it's not a small community, so there are plenty of people that would be affected by any one problem).
Wordpress is integral to their business. If they run into a WordPress bug, it would be useful for them to have access to someone that could track it down and diagnose it.
Any heavily used WordPress plugins, or custom WordPress plugins might be integral to their business. They maybe should have someone that can look into problems with those.
If a million other people are using the same feature as you that might cause problems, you're probably safe letting the community provide a fix. If 1000 other people are using the feature, who knows how long that fix will take in coming? If the developer is busy, it could be days.
It's a function of how important it is to a business and how rare/replacable it is.
The thing he said before that it's a non-swappable integration of a highly-complicated, web browser. Firefox is a mix of Rust, C++, and C that Mozilla Corp. develops with over a 100 million dollars a year worth of developers. The standards it implements are numerous with many complex interactions, optimizations, security features, extensions, and so on. And you are saying it's excessive to pay a Firefox developer to made the change or consult on how it works? That instead use an internal developer with no clue about it?
A Firefox consultant in that scenario sounds more like a necessity than an excess to me. If anything, one expert might not be enough given they're probably specialized to different parts of Firefox. Also, a reason to never want a non-swappable dependency as big and complicated as Firefox. Then, you might become one of those companies that get locked-in like customers of IBM, Microsoft, and Oracle.
That's taking it a bit far, no? A more charitable allegory would be a website design agency that relies on Wordpress for websites, so they have Wordpress developers on staff (or on retainer). That doesn't seem unreasonable.
There are a few such agencies out there: RedHat, Igalia, Credativ come to mind. There are some more listed on employers and freelancing sections of the FOSSjobs wiki:
