Django has a similar philosophy: define your models and they are reflected directly into database tables and you can auto-generate forms using them.
IMO, the trouble is that it couples vertical concerns (presentation, domain, infrastructure). It's fine as long as the domain model has trivial presentational and database representations.
However, if you want to make a complex interface with many convenience features, you'll have to let those requirements bleed into your domain layer; and if want to create complex domain models, it's impractical to enforce invariants at the language level (since anything with a reference to a Model can do arbitrary things to it).
IMO, the trouble is that it couples vertical concerns (presentation, domain, infrastructure). It's fine as long as the domain model has trivial presentational and database representations.
However, if you want to make a complex interface with many convenience features, you'll have to let those requirements bleed into your domain layer; and if want to create complex domain models, it's impractical to enforce invariants at the language level (since anything with a reference to a Model can do arbitrary things to it).