So you propose building a reactor that doesn't have anything actually working beyond demonstration reactors yet?

It still has many of the same issues coal and gas has:

1. Its still centralised. The power companies can still rip us off.
2. Solar is already cheap and already only takes 4 years to pay off. The Government would have to subsidise the power during the construction period to prevent people moving to solar. And, Solar is effectively free after it has been installed
3. It STILL needs instantly dispatchable power. You can't just turn on a generator. You need to spin it up to the correct speed, and it needs to be in the same phase. If its out of phase, the generator jumps forward or backwards and damages itself.. Safety circuits will kick in. Loy Yang's kicked in during the storms. Nuclear will likely have the same issue.
4. It doesn't solve the unreliable power in Rural areas. Whereas, solar, wind and batteries can because they can effectively treat it more like a "microgrid", with less central points of failure.. ie, instead of centralising the batteries, scatter them in various areas.
5. Whilst there is reduced radiation, and its cleaner than Coal, you STILL have radioctive byproducts that will last ages. Ultimately, it doesn't matter how well they're stored, there is always a risk they'll end up in the water table and not secure and it will be expected that a future generation will likely need to use excess energy to convert the radioactive materials to non-radioactive (somehow)

The only real problem it solves is that its more reliable than solar, and cleaner than coal. But.. In two and a half years, solar panel efficiency also increased by 5%. So, in 10 years, that could be a 20% efficiency increase too.. And in 6 years, the cost halved.

In the unlikely case the thorium plant does need to be shut down (natural disaster as an example, similar to Fukashima), we're basically screwed. Microgrid's wouldn't have this trouble.. Also, it basically requires that we just do nothing about the pollution for 10-20 years whilst they're building it, or the extra power requirements we'll need to transition to non-fossil fuel cars.