Had you been alive in 1903 would you have opposed Wilbur and Orville Wright's first flights? Do you think you could have seen what would develop from those first dinky little flights of less than a quarter mile? Do you think you can see what will in the future come of these first passenger flights to space (themselves consequences of the Wrights' first flights)?
These billionaires are spending far less than NASA does. Have you expended an equivalently greater amount of outrage against that federal government agency?
Do you sincerely think the actual choice is between investing in space flight and ending poverty? Do you think that's really the top alternative these billionaires would choose if they weren't funding space programs?
Do you really think if we taxed them more heavily so they couldn't "waste" their money this way that the government would use the additional revenue for social programs rather than this fungible money also funding military programs? Really, do you not understand it would simply, at best, reduce the deficit by a very minuscule amount?
Do you not understand that private investment has been the driver of the economy that has made us all, and especially the poor, far better off than people were in previous generations?
This very brief trip to the edge of space, despite not even achieving orbit - the equivalent of the Wright brothers' very short flight - is a big breakthrough, because it is the first time space flight has been made safe enough for mere tourism. Just as cars, phones, television, and air travel were initially affordable only by the wealthy, this is just the first step in space tourism. This is the first step in something that may dramatically redirect humanity's future, and provide fantastic opportunities to our descendants that we can only fantasize about now.
Maybe instead of automatically reacting to the social justice bat signal, as others have programmed you to do, you think this through a little more, with some sense of history and some understanding of economics. I guarantee it feels better than being addicted to outrage all the time.