Well, when 60-100 million children starve to death every decade, when another 800 million people annually are malnourished, when 20,000 square miles of ocean are clogged with plastic contamination, when we are 30 years away from no more oil, when 10% of all college age blacks are in prison in America, when 50 million Americans are without health insurance, when we have no long term strategy for storing spent nuclear material, when 250 million people contract malaria every year...and a whole host of other issues, I say the money spent to satisfy people's curiosity is the bigger crime.
First of all, I would say that if you live a life without any luxuries, then your moral standpoint is unassailable. Otherwise not so much.
Secondly, I would say that scientific knowledge is one of the most economic of luxuries. We pay for it once, and then everyone has it forever.
(An anecdote: some guy protested at the cost to the taxpayer of turning me into a mathematician. I did a quick sum in my head and gave him a penny as his refund.)
Thirdly, I would point out that it is difficult to know in advance whether a piece of knowledge might have practical uses. SETI is
now a classic example of a waste of money. Unless and until we contact aliens who share with us their advanced technological secrets, in which case it's the motherlode.
There was a guy, I forget his name, who made such major practical advances in physics that they gave him a Nobel Prize for it. His research was instigated by his curiosity as to why the Mediterranean Sea was such a beautiful shade of blue.
Obviously if we knew
in advance what would be useful we'd all be doing that.