A couple caveats.  A uniform 1" seeding depth for wheat may be optimal in areas without winterkill issues (mild winters, no sudden changes in temp).  Where winterkill is a problem, I would prefer to see 1.5" minimum. 

Another issue is getting all the seeds to a certain depth in no-till conditions.  It's extremely challenging to cut a furrow only 1" deep and get a clean cut on the straw and surface residue.  Wheat seeds in hairpinned residue either don't grow at all, or are extremely feeble.  This can be a far greater yield robber than planting slightly deeper.  For example, the JD 50/60/90-series gauge-wheel drills usually hairpin stubble badly at 1" depth (depending on conditions), but they get reasonably decent at 1.75 - 2.0".  This is with 18" blades on the Deere, and using adequate downpressure and frame weight.  Some drills with 22" blades are even worse about hairpinning.

Some farmers in Australia and the PNW are using row cleaners on their drills, but this has its own set of problems.

[Edited to fix formatting problem]