Agreed. This 'but we wanna make millions with a dual license as that 0.000001% of open source products do' attitude is definitely the largest barrier for this. And it's incredibly short sighted; just open up (L)GPL and do services + support. All big companies WILL buy support as that's what they do. AGPL is crap and will stop your growth; you have an uphill battle already, so don't do stupid things like that.
Eh, they don't need to just let everyone use it for free. I would say: put it under an open-source (LGPL, for example) license, but charge people for the downloads (including for updates). Nobody likes using software that never updates nowadays, so with low update-prices you could get reasonable amounts of revenue-per-user over time.
If I came across software that was LGPL but charged for downloads, I would very quickly google to find someone who provided updates for free. And if that free distribution channel didn't exist, I would create it.
Edit: the below isn't a very good answer to the issue; I will leave that anyway. But it boils down to that in order to divert responsibility in a big company, you have to show you did all you could and to do that all you could, you need to show you paid money to 'the head ninja'. This could be MS/Oracle/IBM: very safe. When using Open Source, you need to show as well that you did all you could when it fails (if it succeeds, the company wants to be in the news using open source to 'cut costs') and so you pay people who can support it (the original devs) large amounts of money to support you. TL;DR It's covering your ass.
Previous reply;
You haven't worked with big companies before then; they pay for support (and licenses if needed). It's how it works as it is a liability thing; if you pay for something it's better than free as free doesn't exist. And that's kind of true; for free open source you need highly skilled employees to maintain it while you can also buy support from the company who actually built it. TL;DR big companies buy your support if they use your open source.
Because big companies are marred by red tape and bureaucratic policies which require them to spend money on support rather than figuring it out themselves.
Most projects eventually encounter thorny issues. If your only recourse is to let someone smart go into a deep dive while everyone waits, a lot of bad things can happen. You might not even have anyone with the wits and drive to fix it, or you might get a terrible hack that becomes a maintenance black hole. Meanwhile, your schedule becomes a question mark, naysayers against the technology form cliques, etc.
Small teams of motivated people can make just about anything work. For everyone else, support makes project schedules more predictable and can avert certain painful scenarios.
