It's enough to purchase ONE item to Xûr per week.
By having three characters at 28, and be willing to repeat the same strike 3 times on them.
This is some hardcore shit, not everyone is playing like this, far from it.
Doesn't change the fact that your assertion was not an universal truth.
For some people like me, not having Xûr would mean quitting the game earlier than having him in the game.
A proper fireteam can rip through the nightfall 3 times in 2 hours. As long as you coordinate, you can get around any weapon deficits your group has. I remember the Devil's Lair nightfall had arc burn one day, and I had no arc weapons. I tried soloing, and it took me 20 minutes just to kill the two fallen captains in just the first wave. I died trying to speed through the second wave faster. I went back into that nightfall later that day with two friends, who didn't have arc weapons either. We just coordinated. Sniper, fusion and shotgun. Sniper kept him reeling from the impact, fusion rifle helped drop his shield, and I ran in with my Universal Remote and finished them off close-range. Cleared that nightfall in 40 minutes or so.
My clan is composed of guys in their late 20s to early 40s, most of them married, and we all work full-time. One of our guys even works on the road, and has raided with us from a motel. We only get a 4-6 hour block each night where we're on together. Our week looks like this:
Tue - Nightfalls
Wed - Weeklies/Raid (Oracles-Gorgon Maze)
Thu - Raid (Gatekeepers-Atheon)
The rest of the week varies. We only require 3 games of coordinated gaming, and even then it's not that much. I don't even do the dailies anymore. I have so many assmats, I've taken a short break from doing them. Nightfall on Tuesday so everything earned that week is boosted. It really only takes about 2 hours if your group is competent. \
Weeklies can be solo'd pretty easily, but with a fireteam, shouldn't take much longer than the normal version of that strike. That sounds weird, but the elemental burn usually makes it easier to kill enemies than the normal strike. Dailies can be solo'd pretty easily too.
Anyway, it's not that hard to fit in the major weekly events with all 3 characters. I'd say a 7-8hr commitment spread across the entire week isn't that bad. It does vary with skill level though. PEACE.