Without a significant change in general consumer behavior or significant improvement in manufacturing technology, it will require a dramatic change improving water blaster technology to get consumers to notice and once again seek out better quality, higher performance water blasters. Improvements in mass-manufacturing techniques may help slow the further deterioration of water blaster quality, but unless the $15 USD price point ceiling can be raised, the likelihood of a higher output performance water blaster being released in retail stores is extremely low for the foreseeable future. Unfortunately, for those of us seeking better performance, we shall need to find alternate, creative paths to acquire or attain the soaking capabilities we seek.
While I don't have all the information, here's what I do know:
I don't see risk taking from manufacturers. How about they try releasing a higher performance blaster to see how the market responds? If retailers won't take these blasters, Kickstarter seems low risk to figure out what sort of blasters might sell. If the price is high, that's okay, just say so! You don't know if it will sell until you try.
Further, I don't see manufacturers looking for new markets. Selling to retail outlets as has been done since the 1990s no longer seems viable. So why focus primarily on that? Manufacturers need to try something else. Selling directly to consumers would be a start. I can't even buy the Drench Force because the blaster appears only in some regional stores. It might be that most people who might want the Drench Force can't buy it! Selling online would largely avoid the shelf space issues that have been discussed at length as well.
Given the mentioned points, it's hard for me to not come to the conclusion that manufacturers have given up. Ultimately, there's little we can do to influence manufacturers aside from post complaints like this. It seems to me that our path forward is better homemade water guns. The community can't grown much until we solve the blaster sourcing problem.