Time is the most important thing in 1 minute chess, yes. However the ratings aren't meaningless. I've won games on time in 1 minute chess where I am clearly behind on the board, and sometimes my opponent may complain, but if the roles were reversed, and I had their position with only 20 seconds left, I would have won easily.
So it's about the defensive and offensive patterns you have memorized. My immediate impression of a setup that offers resistance was stronger than their immediate impression of how to convert their advantage (or their lack of impression, if they're reduced to shuffling pieces around).
But to answer the question in your title, it's fun because you don't think :) The sequence that immediately pops in your head (from years of experience you just have these series of moves as ideas) you don't have to check, or think of something better, you can just try it out. Esp. when it's aggressive. In a real game you may never go for this aggressive sequence, but it's a 1 minute game, it's not a serious investment in time or energy, just go for it and see what happens!
most of the 1 min games i have played / observed seem to be won on time not by the better player but by the player who moves fastest am i wrong or right let me know what you think.