...And six years after release WOTC still does not fix it (like the lucky feat, ranger class or the abjurer-warlock with the cloak of shadows, The fact that you can use action surge with spells, etc) so I think this is intended or they do not fix it because it could create a backlash.
What makes Divine Smite too strong is that you can choose to use it AFTER the attack roll. Most abilities that trigger on attack rolls have to be used before and this was never updated.
And also you can use it many times as long as you have spells available to continue smiting in the same round. Other features, like rogue´s sneak or monks`furry of blows you can only use once per round.
