The English word peace does not come from a root meaning "absence of violence," but from a root meaning "agreement," as in the related word pact.* Etymology is not meaning, as semantic drift is constant, and over a few thousand years a meaning can become unrecognisably different. Peace in 21st C America does indeed mean "no war" and I don't want to suggest otherwise.
But it might give us some insight on how our forebears thought about peace. Significantly, the older meaning would have been more prominent in their minds when they heard the phrase "Blessed are the peacemakers," as even the presence of the word "-makers" would suggest. They knew that peace was not always made by just going away and refusing to fight. Peace resulted when there was agreement, treaty, pact.
It doesn't say "Blessed are the peacewanters."
*Proto-Indo-European *pak (just to annoy my sons).