One of the ML textbooks (ESL maybe?) I read described decision trees as (paraphrasing) "really great - they are interpretable, fast to fit, work on lots of different types of data and outcomes, insensitive to scaling and distributional issues, don't have too many tuning parameters...except they just don't work very well." That latter problem can be solved with bagging or boosting, though you are bargaining away many of the other advantages.