Because there's a conflict of interest there - making money can, and often leads to business ending up harming the public to maintain/increase its profits.

Personally, I'm fine with businesses doing work for the good of the public. They should be transparent about it though.

In this case though the statement about "privacy" is seriously marred by the marketing of the product as "Hey, find out if your partner is cheating" rather than going "Hey, see how much we could find out from some vague details?"