I leveled GLA in 2.0 before Flash got a 20% buff to enmity generation and never had any problems, even though I'd never played an MMO before. Enmity shouldn't be a problem to anyone that's decently geared, and if it somehow is a problem then that's the player's fault.
2x Flash generates nearly 50% more enmity than Fast Blade > Savage Blade (1200 vs 850). If someone is losing aggro through Flash/Unleash/Overpower spam even in single target, they definitely aren't "fairly well geared".