Lots of people are trying to apply that cleverness to fission. The problem is that governments make life much harder for fission projects than for fusion projects. There's some justification for that; fission done well is great, but fission done badly can cause much more serious accidents than fusion done badly, and proliferation is much less of a concern with fusion.

Even so, the regulation is more of a problem than it needs to be. The NRC currently requires a near-complete design up front, costing several hundred million dollars, before they even hint at whether they'll approve your project. If they turn you down, you're done. If they approve, you've still just got paper; it's only then that you get to start experiments with nuclear material. If they just had a more incremental process it'd be a big help.

Meanwhile, people build deuterium fusion reactors in their basements and nobody bats an eye.