The bit your missing is the awkwardness of expressing outer joins. The way Oracle does it is an existence proof of its awkwardness.

The 'FROM' clause defaults to Cartesian product for multiple tables. You can then specify your join conditions in the where clause, but it makes outer joins harder to write - Oracle does them with special (+) operator, but it's clumsy.

It doesn't (shouldn't) make much difference at all to the database whether you specify your join condition after the `ON` or in the `WHERE` - if it doesn't hoist `WHERE` conditions into the join clause, and potentially change the join order because of it, it's missing big optimization opportunities.