Ever profile an application? That's what EXPLAIN helps you with. SQL is different from a lot of languages in that it runs through query planner/executor, often based on properties of the actual data which change over time. Not a lot of other programs do this, and certainly not your typical imperative or procedural code. The JVM is one that comes to mind. Do you know of others?
I KNOW what it helps you with. No programming language has a keyword that decompiles expressions to their base components. Also profiling is only done when optimization is needed.
SQL on the otherhand... EXPLAIN is used on a regular basis, it's built in to the programming language and rather then just mark lines of code with execution time deltas it literally functions as a decompiler to deconstruct the query into another imperative language. This is the problem with SQL.
Many application languages have "reflection" API's that can examine internal or low-level code structure. I used database languages such as dBASE (and clones) that are based on more or less on sequential query languages. While I did like more control over the intermediate steps, including the ability to analyze them; the problem is that different people do things too differently. SQL reigns in the "creativity" to a large extent. What works well for an individual may not scale to "team code". Working with a Picasso-coder's code can be a bear.
This is a valid argument. A high level abstraction definitely serves as a restriction over code that gets to "creative" at the expense of obfuscation. Following this line of logic, the argument then truly does become apples to apples.
