Do the Frostbrand and Flame Tongue swords not get a + anything to hit/damage?

@jrhyne1976do the Frostbrand and Flame Tongue swords not get a + anything to hit/damage? Just noticed…
That’s correct. @mikemearls @ChrisPerkinsDnD

— Jeremy Crawford (@JeremyECrawford) June 3, 2015

@jrhyne1976how strange! Any reason for that choice?
A bonus to hit and damage is no longer a default property of magic weapons, which can have a variety of desirable properties.

— Jeremy Crawford (@JeremyECrawford) June 3, 2015