This is quite the conundrum -- isn't it? -- as it's not just "those companies" named in the Snowden documents. There was nothing particularly unique about them

This is quite the conundrum -- isn't it? -- as it's not just "those companies" named in the Snowden documents. There was nothing particularly unique about them that permitted them to be corrupted and compromised other than their nodal market position. If the spirit of your argument causes a perceptible shift in market share to new players, then these too should be instantly distrusted. Even if fully open cryptographic implementations become the norm (which doesn't matter if they give up their keys), remote closed-source services will need clear text to provide service algorithmically. What then?