I think one of the factors that contributes to interest in ad-hoc techniques is the prospect of a "thrilling discovery". One is allowed to fantasize that all of their time and effort may pay off suddenly and unpredictably, which makes the research seem that much more fun and exciting. This is in contrast to a more formal approach in which understanding and progress are incremental by their very nature.

I bring this up because I see it as a likely underlying motive for arguments of the form "ad-hoc technique X is worth pursuing even though it's not a formal approach".