Zontar said:
"Streamlined". That killed Supreme Commander, it killed the X series and it killed Civilization, my favourite RTS, Space Sim and Civilization respectively. Supreme Commander 2 was the "streamlined" pile of shit no one asked for, X Rebirth was the game that never should have been made by anyone, and Civilization V marked the beginning of the the downfall of the Civilization franchise (though most players wouldn't realize it until BB made it clear as day).
The funny thing about Supremme Commander II is that it felt in every way like a game made before SupCom. Worse graphics, less units, less strategy, less diversity, smaller sizes, less interesting campaign... Less, less, less, and I think not a single thing "more".
Which brings me to my personal instant filler in the "fuck-off"-er meter: Sequel chopping. That fun little thing when you remove from the sequel something that was in the original game, for no adequate reason and no satisfying gain. No better example than The Sims, the only series I don't feel bad pirating, because at least half the previous-game's DLC (Or, in Sims 4's case, ALL the DLC plus some base features) are removed, only to be added later and sold back.
The words "Where is X", with X being a beloved feature in the previous game, is enough for me to drop it right there