Even if I assume your premise, why would you assume that this is a more effective way of stimulating demand? (I'm not necessarily disagreeing its just not obvious to me that one mechanism is better than the other.)
As I understand it, the QE strategy is for the central bank to buy bonds. Bonds become overbought, so investors shift to stocks and shares, lifting the stock market. Investors benefit, as do companies seeking to raise funds through share issues, but uninvested consumers do not. As a result, the stock market goes up, and borrowing costs for companies go down, but the "Real" economy stagnates. Companies can borrow easily to fund expansion, but have no real market to sell into, because the stock market is disconnected from the underlying "main street" economy. Basic income provides another mechanism for Keynesian reflation, but targets the "real" economy rather than the stock market, so stimulates actual demand, rather than pumping up the bubble. Of course, inflation is a massive risk with both of these strategies ... and may happen more directly and more quickly with the basic income strategy rather than with QE ... so on second thoughts ... it might not be too great an idea.