I mean if you think SQLAlchemy does the job for you that's great! My general contention is more "there are good ORMs". I believe Django is the good one, but if you think SQLAlchemy works well for you, go for it!
They are all useful tools, but I think it's important to keep them in context. I feel like what most people want is the automatic SQL generation from their general purpose language of choice. That and a migration framework. But none of them should be considered a no brainer because they all come with considerable downsides. One of the most difficult things I've found in complex, long running projects is people clinging on to the ORM long after it's ceased to be useful. SQLAlchemy at least lends itself better to proper architecture with it's data mapper, but Django really doesn't like being relegated to a lower level.