I didn't mean to simply every query by just ID, it was an example. The expressions can be rewritten to only columns needed. As an other example, I highly doubt accessdenied.php needs all other 51 default columns of data to find out if the person can view a page. A main issue is that they're calling to the database for every check, there isn't any sort of cache info used so on the home page each block makes its own call to the database, lots of it duplicating queries from other modules.