The myth of a shielder getting valour by just holding right key in a block is really overdone, I would hope this is because us shielders ourselves make an ironic joke out of it to spread it cuz surely people aren't coming to this conclusion through their own careful gameplay analysis??? You might collect some points doing that but won't get enough for valour. Go spectate the better shielders (or melee players in general) who do get valor consistently. At the beginning they are usually in the thick of the fight attacking very aggressively and chopping down people left and right. When I encounter a guy like this I usually go out of my way to check him cuz I know if I leave him alone he'll rip through my teammates, he's my #1 concern not the guy holding up a shield, and not the archer 50 feet away on the side.
And good archers can be very helpful, but no way is their damage per second anywhere equivalent to a melee STR build swinging a big weapon every 2 seconds at least in that critical opening sequence with targets constantly in reach.
Speaking as someone who has played a lot of shielder, I agree getting valor while doing nothing but blocking would be very hard. Still though, you can get a lot of points doing nothing but block, so it makes valor easier to obtain if you are able to land hits & contribute more. I'll do some video testing later today if I CBA.
Speaking as someone who has played a lot of archer, I agree archers don't have the DPS potential melee has (nor should they). Still though, it is VERY hard to accrue points as an archer. I usually get 1-3 points per landed arrow. I would argue that a shielder doing nothing but block in the fray of a fight will outperform an archer landing a lot of hits at ranged more often than not.
Speaking as someone who gets a lot of valor, yes ganging up against other players is a great way to get points in melee, since you're gaining points for the damage you and your buddies deal. Valor isn't completely broken - good players often get it - but it's still broken for ranged.