What do Buddhists think of lottery manipulators?

The question you ask is easier to understand from a different perspective.

If you ask a Buddhist scholar what he thinks of a butcher, then he must be advised to change his profession, because killing karma is heavy and naturally leads to hell.

Your trade can create bad karma in disguise, and you need to take the blame for your sins, for example, if someone loses it all and commits suicide, and their family is destroyed.

Amitabha Buddha