Why is he pardoning a drug trafficker?
But unless you can point to any other group with actual power and money who was pushing for it, the most obvious answer is that the main funders of the crypto PACs were at least ok with it. There's no way they couldn't have subtly squashed this pardon with Trump if it was just the Libertarians asking for it given that they seem to have gotten him to commit to do literally everything else they want.