You gathered wrong.
A couple MAJOR flaws/pitfalls of Thorium reactors paired with molten salt coolants (they are separate components, you can have molten salt reactors with Uranium as well as LWR (light water reactors) with Thorium) include that:
1 - Thorium-232 is fertile, not fissile. This means it reqauires a neutron to become Thorium-233 which then is fissile (naturally decays, and fission into??? --> Uranium-233). Normal reactors use U-235 enriched as the naturally occurring isotope is U-238. There is no advantage except maybe that you could say Thorium is more available than Uranium, but the cost of current nuclear tech is >90% regulation & design/construction, the rest being the cost of fuel so there is little to gain here. Uranium is also ubuiquitous and essentially renewable in the quantities available vs. the amounts humanity could possibly remove from it.
2 - Molten salt reactors (unrelated to Thorium) is simply there to achieve heat transfer at higher temperatures than at water to improved the Carnot efficiency of a heat engine. eta = (T_h-T_c)/T_h. This means that essentially the hotter the reactor can get, the hotter the working fluid, the more efficient. The problem with water is that past 100C is try to boil. Some reactors are PWR (presurized water reactors) that pressurize to prevent boiling, others are BWR (boiling water reactors) which take advantage of actually allowing the coolant to boil. Each has advantages and disadvantages and they are near identical which is why Westinghouse and GE compete so healthily. Molten salt reactors on the other hand have coolant that would boild at several thousands of degrees so sure, you get added efficiency because you can run your reacotr much hotter than a LWR without added pressure. The MAJOR negative is that in general, things corrode more easily at higher temperatures and salts are extremeley good at that. Pair the fact that the coolant will be moderatley radioactive and you have a potential corrosion catastrophe. Any piping needs to be orders of magnitude more corrosion resistant than the materials used for water pipelines (of which doesn't exist). This makes the reactors more likely to endure a LOCA (loss of coolant accident) in regards to leaking though it is granted safer in terms of pressure.
3 - It's fuel is worse (depleted). Because these materials aren't fissile, it needs higher neutron fluxes to activate as much energy as a Uranium reactor. More neutrons --> more neutron damage to materials, more neutron capture by impurities, when paired with the comparable fissioning of a VERY active U-233, your spent fuel is highly radioactive. There are advantages and disadvantages. Thorium fuels stay radioactive for short periods of time, but this is because they are more radioactive in the short term. It's the same tradeoff with how you can hold natural Uranium in your hand (radioactive) because it decays so slowely (basically for ever), but if you have an activated chunk of titanium you better stand back because the half live's of its isotopes are minutes long so all that energy is discharged like a capactitor.
TL;DR Thorium ( a fuel) combined with molten salt coolant (a reactor type) is overhyped as a superior alternative to Uranium light water reactors. It is interesting and research should be encouraged but, the tradeoffs with Uranium/Plutonium even out and to date the most serious research is still involved with Uranium reactor technology as after an extensive PRA it is still the safest for of energy to date.
On the other hand, all technologies are comparable except that uranium/plutonium reactors have one MAJOR advantage: