I was about mid-game when a new minor race (the Vegans) entered the galaxy and won a tech victory in about 10 turns. How not fun is that? If I had been going for a tech victory (luckily I wasn't) that would have totally sucked.
Additionally, they had technology way beyond what they should have - Blackhole weapons, etc. It was to my advantage because I traded them for it then invaded their planet - but they shouldn't have had it in the first place.
Maybe "Turn off Major Events" should be renamed "Turn on Fun".