"If you could..."

I was thinking about this incredibly passive phrasing.

• "If you could finish this, that would be great." 
• "If you could move your car, I'd appreciate it." 
• "If you could email me the schedule, that would be great." 
• "If you could..." 

I use this phrasing all the time, both in real conversation and in email, to family, friends, colleagues, and students. Hypothetical situation: A student in my smaller class keeps her backpack on the table. I don't know that she's quietly texting behind it, but it's a possibility. When I rehearse what I would say, hypothetically, to this student, it always comes out, "If you could move your backpack to the floor, that would be great." 

Working with little kids, I was able to be much more direct. I would say, "Backpacks go on the floor. Thank you." (Or  maybe I'd compliment Junior on his right, and say, "Junior! I love how you have your backpack on the floor. I bet that gives you so much more room to make your art project!") 

Is it a Girl thing? To constantly and subconsciously soften statements? To raise our voices at the end of a declarative or imparative sentence? To be indirect? Or maybe it's just a Me thing.