First of all, we all know D. are the ''natural enemy of the gods'', so whose are natural enemies of the gods for real? The Titans. And the titans are known for destroying everything in their path.
Rosinante also says that in his country people tells kids that if they don't behave ''D. will eat you...'' and the people say ''D. will cause another storm...'' (Manga Chapter 764)
And here it comes ;
''If celestial people are commonly considered gods... Then your goal might be... to destroy the world...''
Another translation from the manga chapter 764 ;
''If you view the celestial dragons as the gods in this case... then perhaps your people 's goal is the very destruction of this world.''
Bald Gorousei also states that D. ''always causes troubles'' ... By causing trouble, it could be easily ''destroying things''...
- Manga Chapter 594
Trafalgar D. Water Law
Law : ''I want to destroy it all.''
This is what little Law says, he was born for destruction.
The first time we've heard of Marshall D. Teach ;
''With overwhelming strength, they destroyed our entire country in the blink of an eye.''
Let's look at Monkey D. Garp, despite being a Marine ;
Tsuru : ''You always destroy the ships.''
And later, a prophet claims that Monkey D. Luffy will destroy the Fishman Island ;
''By his hands... !! Fishman Island will be destroyed!!!''
He was trying to destroy Noah, and he destroyed half of it ;
''Noah's been destroyed !!''
Monkey D. Luffy : ''If I don't destroy it, the island will...!!''
''Arlong Park is destroyed !!''
Marshall D. Teach was trying to destroy the Marineford island ;
Sengoku : ''The 'Justice' known as morality will not be destroyed !!''
Monkey D. Luffy and Water D. Law's alliance ;
Marine Officer : ''Dressrosa has been thoroughly destroyed !!''
Another Marshall D. Teach moment ;
''Blackbeard Pirates had already destroyed the place,''
Gol D. Roger, the pirate king, destroys an entire army just because they talk bad about his friend ;
Garp : ''One time he destroyed the entire army of a nation...''
I don't know, but it looks like ''Destroyer'' is a very suitable name for them, I wouldn't be surprised if not though, it could be something Japanese too.