In general, upgrades on United must be supported with an upgrade instrument. Full-fare economy does get a "complimentary" upgrade but not the lower-cost fare classes.

United has far, far more elites than US. There is just no way they could do automatic, free upgrades. If you want to upgrade, support it with certificates or miles - or purchase a buy-up. I think you will find little sympathy here for your anger. Most of us prefer it the way United does it. At least this way, mid- and lower-level elites have a chance of their upgrades clearing rather than always being bumped by higher-level elites getting "free" upgrades. If I, as a mid-tier elite, want to burn some of my e-500 certificates or miles, I can often clear the upgrade. If I were competing with all the 1Ks out there for "free" upgrades I'd rarely clear.