Actually, the airline pilot uniform traces its origins back to commercial maritime uniforms. There was a time when airlines were competing with ocean crossing passenger ship traffic and because of this, the airlines chose that style of uniform for marketing and image.

Now, I suppose an argument could be made that the commercial maritime uniforms have military roots, but the jury is still out. There are accounts of some pre naval merchant and exploration ships' crews that had a semblance of a uniform that indicated their position as to make it easier to bark out orders to configure all those sails. I'm a geek. That is all. Carry on.