Because boiling everything down to a simple model like "regions where bombs are likely" is throwing away information. We do so because it's easier to analyze a

Because boiling everything down to a simple model like "regions where bombs are likely" is throwing away information. We do so because it's easier to analyze and think about a simple model than to try to deal with the whole dataset all at once -- except that if you have a specific question, it might be possible to treat that question directly. Because you're not losing information, doing so provides a more accurate result. In practice this might not matter, and simplified models might be good enough. But as computers become more powerful, it becomes easier to query the data directly.