You only need to do a single point of damage with deathtouch to kill a creature, so the rest of the damage hits an opponent with trample
Equipment decks will run it for sure, but it lacks the splashability of something like Cloud, Midgar Mercenary
If they boarded in Hallowed Moonlight, they were stuck tapping out to ramp and dying with it in hand or leaving up mana, doing nothing, and dying to mediocre beats
So, in practice, it's like paying extra and getting a bonus just remember that, technically speaking, there are important differences between an alternative cost (like evoke and overload) and an additional cost (like kicker)
Disclaimer: Some of these cards may appear to having some spelling errors and/or mistakes, this is partially due to the cards themselves as well as the text settings on tappedout