They probably did not do a cost benefit analysis between the two...

They probably did not do a cost benefit analysis between the two because (Carbon Hard facing) directly applied or by the way of extreme temp bonding does not work. The hammers barrels are too thin for what you are suggesting and they crack and or distort while applying Hard facing if not while applying soon after through the cooling process.
Hard facing works OK for larger stabilisers and reamers, I worked for a company that has tried what you have suggested and it failed on all occasions.
Not sure how Laser bond have achieved what they announced but it sounds like it works.
Will keep an eye on this.