Why should people who pay virtually no taxes get a tax break?
Simple as that.
Reminds me of the Billy Preston song, "Nuthin' From Nuthin' Leaves Nuthin'"....
They may pay little or no income tax, but all the other taxes still apply: sales tax, various local taxes, etc.
But, it should be obvious that someone who pays no income tax, cannot get a "reduction" of their income tax. You can't reduce something to less than zero.