In my industy, which is very technical, you need a lot of space to explain what you do. A professional resume writing and job hunting firm I hired with expertise in my field came back to me with a 3-pager after I'd spent a long time trying to keep it to one and then two pages but being frustrated with that because too much was left out. Turns out what I thought was this universal "rule of thumb" was just my ignorance.

When it comes to something as important as hiring, more information is better.