Freestyle swimming leg position

sounds like he's got the wrong way around.  I can't kick for toffee... so only use my kick to keep my legs high and therefore reduce drag.  I mostly swim with my arms, and I think most other people do too....

I think it also depends on what you are training for.  For short distance swimming events your coach is spot on.  You need to use both your arms and your legs to get through the water as fast as you can.  In this situation your legs do tend to provide the majority of the propulsion.  Have a look at how far the swimmers were going using just their legs when pushing off from the wall in the Olympics, or even some of the paralympic athletes who didn't use their arms.

But for longer distance events then your arms do most of the work and your legs are there for stability and to provide additional short term drive if you need it.  Leg position is important for streamlining.  I try not to splash with my kicking but keep my feet just about breaking the water a little.

For triathlon you have the added complication of wanting to keep your legs fresh for the bike and run, so you tend to use your legs even less

I'd argue that a lot of triathletes are not V-shaped as their legs are proportionally stronger than their arms, compared to elite swimmers. So, don't waste your best asset (your legs) by barely kicking at all.
However, kicking thin-air by moving your feet up above the surface of the water isn't going to propel you at all, no matter how hard you kick. I think that's the laws of Physics!

Just for reference Chris Poole 9, Supercaz is a well respected swimmer and Siggy can get a bit of a shift on for an old fart too.

Personally, I use the legs for minimal, but essential, propulsion. As well as stabilisers. This is done by "walking" in the water horizontally. 

Flat out in the pool, legs come more to the fore. I also try to keep as little out of the water as possible, Out of the water it's dead weight and pushing you down.

Just my thoughts. 

I dont know how you would get your feet 10cm out of the water. 10cm is quite long, as I recall from that last time a measured anything against a ruler.
Feet will be a bit higher in the water if in a wetsuit, dont know if that's what he mean, but it still sounds a bit weird.

85:15 arms:legs is normal for most swimmers. So the ratio is right but most propulsion definately comes from arms, unless you have more than two legs.