Suppose the government issued a financial asset that, adjusted for risk and liquidity, promised a higher rate of return than any alternative asset. The government can do this, because it has the power to tax. Everybody prefers holding that government-issued financial asset to any other asset.
There would be an excess demand for that government-issued asset. The only way to eliminate that excess demand would be for the government to buy up all the other assets in exchange for that asset. The government would be operating one big closed-end mutual fund, that owned all the assets in the economy, with people owning shares in that mutual fund. And the rate of return on those mutual fund shares would be guaranteed by the government's power to tax.
Most people would be against that policy. Perhaps we could call the few people who supported it "Mutual Fund Marxists"?