MMT largely rejects interest rates (and monetary policy in general) as a useful tool in macroeconomic policy in favour of fiscal policy. The general position is that since the marginal cost of money is basically zero, the markets in useful stuff are better able to operate if the money markets don't complicate things, and that monetary policy is not a very good tool to achieve the desired objective (weak, and potentially counterproductive at times). If a particular political objective is desired, then use more direct government tools to do that - laws and regulations, rates and duties.