I don't see how both companies being involved with manga makes it possible for Viz Media to buy out 4KiRAB. I believe that the only manga that 4KiRAB is connected with are the different Yu-Gi-Oh! titles and Dinosaur King. That doesn't really seem like a big incentive for Viz to buy 4KiRAB, especially when I think Viz gets a larger share of the profits for manga than 4KiRAB does. Plus, like Andrew mentioned, they don't have enough money to even do so right now.
While I wouldn't have phrased it exactly like that, I do agree with it. I understand that the DVRAB for some of those series didn't sell well, but I believe that they didn't really give them a chance to do well, especially with MAR and Zatch Bell. Considering the amount of money it takes to license and dub a series, I think that it might have helped them to release all of the series on DVD. It wouldn't be a huge as their sales for Naruto, Death Note or Bleach, but they could have done fairly well.
Anyway, this is sad news. I feel bad for those people that lost their jobs. It's really tough in this economy and it's especially hard for people with families and loved ones to take care of. I can also imagine the stress that they could be feeling. I hope that they're able to find jobs soon.