I'm okay with the Rebels wearing that jersey as they are channelling the Eureka Stockade mythos, but some of the others are a bit less justifiable. Tahs and Blues can both justify theirs (I figure if your team is actually named the Blues, you are allowed a blue jersey). The Bulls have Currie Cup precedent so they get a pass too. Stormers, well at least they're a unique shade.
The Brumbies, Highlanders and Jags have no excuse, since all three of them have established jerseys of other (very bright) colours. Make 'em go back to white, green and orange!
The insistence on blue seems especially odd given the established link between wearing red and winning which has been confirmed in multiple studies. Seems to work for the Crusaders and Lions at any rate - the Reds apparently didn't read the literature.