I play for fun, but I rarely have fun unless I'm playing 1v1 automatch.
I guess the underlying question is:
What is it about the competitive aspect of a game that people don't find fun? Or what is it about the single-player aspect of games that makes it more fun than multiplayer?
In my case, I've played so many single-player games that they all end up feeling like battling with excel sheets in the long run. The only fun I have playing video games is in multiplayer. There are rare cases like "The Last Of Us" that still manage to draw me in, but that's about it.
What I don't find fun about competitive aspect of the game?
6-7 out of 10 games my opponent is inferior and represents no challenge. Some people get 10-20 winning game streaks and they are overjoyed, I get 10 game wining streak and I don't wish to play anymore. (I don't mean this as insult in any way, I believe everyone should play what they enjoy)
Thats why I prefer team games, where other players compensate for inferior players and you get more balanced games that actually last longer then 15 min, and have swings, players doubling up on 1 and generally unexpected things that happen during the match.
I used to play 1v1 games in VCOH, mostly vs friends who were similar skill (custom game) or vs friends who are inferior where I would use only infantry or only eng and mines.
I get sick of ranked 1v1 quickly from 2 reasons, win to many games with no challenge and seeing/using same tactics/builds game after game.
Hope that helps you understand
P.S. Playing competitive and for fun doesn't reflect mode you play. Competitive by definition means you want to win and rank up.
For example a lot of skirmish players are competitive in nature and they are proud of their 80 game win streak vs expert AI.
Likewise, playing competitive game has its element of fun. Its the element you draw most satisfaction from that is deciding factor when it comes to which game mode one plays.
If one hates losing and wants to win badly, one is most likely to play 1v1 or 2v2 arranged team because one will have rage attack when losing because of random teamates. If one hates losing even more than average 1v1 player, one plays skirmish.
My point is that its unreasonable to think that people don't play 1v1 because they are scared primarily, and assuming that everyone who plays anything other simply isn't 'good enough' for 1v1.
People just play what they enjoy
I agree with you, I personally can't stand skirmish, or arty fest like Sheldt. But, hey a lot of people enjoy it. Cannot say they are wrong for playing it