I sort of agree: hitting the highest priority tasks first is a generally good idea. However, there are often small 10 to 30 minute tasks of lower priority that still make sense to clear for many reasons: cut down on synchronization effort with co-workers, free up even your subconscious mind from thinking of them, etc.

Also, sometimes we may have to wait for an hour for a very large build to run. Sometimes you can stay on the same task by editing code, designing, etc. but often these delays are great opportunity to clear small tasks.