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.
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.