Being a casual player doesn't mean you want to keep playing yesterdays content. The problem this game has is that it's constantly gear-scaled. A new patch is released, a new bunch of dungeons come out and a whole new set of gear to grind up. Also, a whole new bunch of item levels required to take part.
You could 'casually' obtain Novus over the course of a year, but what would that achieve? You'd have a weapon which is not only unfinished, but completely antiquated even in its final form. Feel free to clean off the cobwebs, just don't expect it to be of much use for any of the 'current' content at that point. By which point you've already been able to obtain a nice level 110 or better weapon which does the job just fine. Ultimately you have to ask if it's worthwhile. I'd argue most would say no.
If they wanted relic to be casual friendly, they should have made the quests worth doing. People don't notice the grind when they're enjoying themselves, it's a fact. I didn't mind getting Zenith on every single class because it was varied and entertaining. I know that once I beat X mobs, kill a chimera, a hydra and three primals along with a few trades I get a shiny weapon. It has a fixed time frame I can work with, and a clear number of steps.
Moreover, each one of those steps is different and not repeated. Each boss fight has its own rules of engagement, and even a chance for loot to help your progress in future battles. It's like originality died after Zenith. It becomes a random grindfest. It's random whether you get your atma, it's random whether your Fate will spawn. It's random whether there's enough tanks and heals for your duty finder. It's random whether you can get that extra meld on your scroll. It's random if you get the item at the end of your dungeon.
...and for what? A weapon which offers NOTHING special. In fact, it's actually 5 levels LOWER than the current 'best' weapon in the game. So... why do we want this again?