No idea what the specific circumstances of this are, but just noting a few things from experience (outdated experience, being 15+ years ago):
- voice acting is VERY well paid for the time worked. IF you are good at it. By 'good at it', I don't just mean the quality of the performance. I'm referring to the ability that the better voice over actors have to just walk into the studio, read their lines and nail it on the 1st go, do a quick 2nd one for safety, and get their paycheck. Congratulations, you just earned $2000 in 5 minutes. Obviously actual dramatic work doesn't pay as well (per unit of time) than ads, but I expect it's still very good money if you're efficient, and much less so if you need 20 takes, or if the director has to stop and explain the script to you all the time.
BUT
- it falls into the same trap as all professional acting work. The money is excellent per unit of time worked (even for minor parts - so long as you have a line, or can do something that classifies you as a 'minor character' instead of an extra, the money is good for the time spent), but even out of 'genuine professional actors' (i.e. not 20 yr old hipsters calling their indie co-op professional theatre while being supported by their parents) probably about 0.5% have enough work to avoid needing another job. That's okay, you're not heart surgeons, it isn't an industry where anyone can legitimately claim a 'moral right to be employed'. But it's a real problem when producers demand that you are available on their schedule. From a purely business outlook, if you're demanding that people have the availability and commitment of a professional, and who aren't going to call up and say 'sorry, my real boss needs me to come in tomorrow', you need to find a way of allowing them to make it their full-time job. Some employers (radio stations that deliberately use the same cluster of voice-actors for their ads, many cartoon producers) are really good at doing that - they'll actively try to fill the gaps in your work schedule in with minor parts, rather than hiring a different person for each such that none of them can make a living out of it.
AND
- the efficiency of the production team make a huge difference to working conditions. It's irritating as fuck to spend 3 or 4 times as long sitting around waiting for the lighting or sound tech to get their shit together, than what you spend filming. Fine if it's a big production and you're getting paid for that time anyway. Pretty shit if you're on a fixed fee, which a lot of voice acting gigs are.
Short version: it's entirely possible that the strikers are full of shit, but bear in mind that there's often more to this than the rate of pay.
Edit: just finished reading the thread, and I've noticed one thing that the developers have overlooked. If they want the voice-actors to get paid at proportional employee rates, like their own staff do, then they should put them on retainer as employees. All but the biggest names would jump at that chance. It isn't unheard of - BBC, some of the cartoon networks and others do it - that way the producer gets full control, doesn't need to pay residuals, and the actor gets security.
Otherwise they're bitching about independent contractors acting like independent contractors. If you hire a plumber to fix a tap, they'll charge an extortionate rate too. That's their fee for not knowing whether they'll have any work the next day. Employees get paid by the hour in return for flexibility, contractors want their pound of flesh. Yeah it seems silly that 'NPC 423' wants his residuals, but it's not his project, not his team, not his company - if they want him to work on their project, and aren't going to retain him as an employee, then of course he's going to demand whatever fee works best for his business.