Whataboutism is designed to deflect attention from a particularly egregious example of malfeasance, corruption, incompetence etc. by claiming "everyone's doing it, why pick on my guys?"

Palantir really is much like the private mercenary firm Blackwater - they seem happy to sell their services to anyone with little consideration of the consequences, rather like IBM in the 1930s who saw the rising authoritarian regime in Germany as a good customer, with no concern for what their technology might be used for. This is remarkably similar to Palantir's eagerness to sell their tech to Israel, where it seems to have been used to aid in decimating the Palestinian population. This exposes Palantir to the same kinds of charges IBM faced, as long as we are making that comparison.