The question can be posed to investments and passive income as a whole.

I do not think these things are "unbiblical," unchristian, or inadvisable as a rule, but I would point to what is being done with the time and effort that is freed. Are you sipping mai tais on a beach with naked freaks? Or are you using those hands to build someone's shelter, using your investment prowess to reinvest back into a community?