[imtringued]

It is because there is no reason why you should waste your time optimizing a page with a heavy query (with thousands of inserts) from 10 seconds to the theoretical 6 seconds that are possible if its only going to be used 20 times and the rest of the time it's simply loading the last cached result?

Also from my experience the performance problems are completely divorced from ORM/not ORM. Usually the reason why you drop the ORM is that you want to take advantage of features that are not modeled by the ORM. Most query optimizations simply involve trying to do everything in as big of a batch as possible. Whether you do batching with or without the ORM isn't really relevant. The reason why people don't batch their queries when they use ORMs is because it's so trivial to not do so but there is no reason why we can't build better ORMs that make batched queries as easy to use as non batched queries which would get us both performance and convenience at the same time.