That's why models are refined over time. If we threw out everything from any theory or model that failed, we'd have thrown out Continental Drift and not gotten to Plate Tectonics, for example.
I don't believe these are good models. I don't believe we know nearly as much about climate change as these "scientists" would claim. I also believe many of the sceptics overstate their claims against climate change. Both sides are acting politically, not scientifically, and both sides have honest scientists...who are acting scientifically despite their personal beliefs in what is actually happening.
Disclaimer: I am biased against Penn State's Earth System Science Center because of interactions with some of its personnel in the past.
When a hypothesis is falsified it is falsified. Models are hypotheses. Their models have been falsified, they and perhaps you just don't accept it.
CO2 has risen linearly while temperatures have not risen at all for over a decade. The hypotheses that CO2 is responsible for Global Warming is thus falsified.
In point of fact the physics is such that any doubling of CO2 can only account for a couple of degress C of warming. No scientist has ever demonstrated any positive feedback and including high feedback gain in these models is a joke which is why the models predictions weren't even in the city that the ballpark is in.
Climate systems are not well understood which is why making predicitons about same is a fools game.