The problem with writing all your SQL "by hand" is that it's needless code duplication.
Set aside databases for a moment. Let's say that instead we're going to generate a bunch of different types of documents, all in the same output format (PostScript or LaTeX or HTML or whatever). Which approach would you take to this problem?
A) For each type of document, manually write out the necessary code from scratch, starting over again each time, or
B) Write some general-purpose libraries which understand the output format and expose an API that you can call programmatically to generate the documents?
I don't think anyone would choose (A) in this case. But many people do choose, and pride themselves on choosing it, as soon as we change from any other use case to generating database queries. Why do we suddenly have to throw away everything we know about writing libraries and avoiding duplication, just to pretend that typing out some SQL makes us "real programmers"?
ORM, in essence, is nothing more than this: a convenient API you can call to do database queries. Why should it be so different?
Set aside databases for a moment. Let's say that instead we're going to generate a bunch of different types of documents, all in the same output format (PostScript or LaTeX or HTML or whatever). Which approach would you take to this problem?
A) For each type of document, manually write out the necessary code from scratch, starting over again each time, or
B) Write some general-purpose libraries which understand the output format and expose an API that you can call programmatically to generate the documents?
I don't think anyone would choose (A) in this case. But many people do choose, and pride themselves on choosing it, as soon as we change from any other use case to generating database queries. Why do we suddenly have to throw away everything we know about writing libraries and avoiding duplication, just to pretend that typing out some SQL makes us "real programmers"?
ORM, in essence, is nothing more than this: a convenient API you can call to do database queries. Why should it be so different?