I don't think this is surprising either. The whole "trickle-down economics" arguments for such tax cuts have always sounded... bullshit (for lack of a better word), exacerbated by the fact that decades of it (since the Reagan era in the US, for example) has only served to make the rich richer, poor poorer and erode the middle class completely. If it was a brilliant idea (i.e. the idea that the the only thing holding back the rich from elevating everyone else from poverty were those pesky low 10s of percent taxes) that worked, everyone would've been favor of it and we would've eliminated taxes for the rich completely by now.

It's always good to have scientific data and analysis confirm your intuition, though.