The reason there has been no such disruption is that the current pricing model (with the bulk of the costs in the toner/ink) effectively price discriminates between low volume users and high volume users.
If toner/ink were sold at cost, then all of the profit would have to be made in the printer sale. This would cause printer manufacturers to choose the profit-maximizing price, which would be much higher than the current price. At this high price, many light-usage customers would choose not to purchase the printer, and very heavy-usage customers would enjoy a greater consumer surplus (because they would have been willing to pay much more for their high-volume printing).
So it's not that there's anything broken about the current business model — it's just the way that manufacturers can reach as many potential customers as possible. The reason that lawsuits like this one crop up is that third-party cartridge refillers are trying to undercut the printer manufacture on the cost of refills. This makes sense, and eventually we'll find an equilibrium price where third party refills cost somewhat less than "official" refills (which will instead carry more of a guarantee of effectiveness/warranty).
If toner/ink were sold at cost, then all of the profit would have to be made in the printer sale. This would cause printer manufacturers to choose the profit-maximizing price, which would be much higher than the current price. At this high price, many light-usage customers would choose not to purchase the printer, and very heavy-usage customers would enjoy a greater consumer surplus (because they would have been willing to pay much more for their high-volume printing).
So it's not that there's anything broken about the current business model — it's just the way that manufacturers can reach as many potential customers as possible. The reason that lawsuits like this one crop up is that third-party cartridge refillers are trying to undercut the printer manufacture on the cost of refills. This makes sense, and eventually we'll find an equilibrium price where third party refills cost somewhat less than "official" refills (which will instead carry more of a guarantee of effectiveness/warranty).