I do believe the difference between the old days and today has a lot to do with the more common use of leds compared to traditional mh and t5’sI don't think you guys really disagree about much. You all (probably) agree that throughput is important. I think whether you can pull off lower nutrients (e.g. NSW-level nitrate and phosphate) nowadays is tank and aquarist-specific and also depends on whether you have dry rock or live rock and is potentially even coral-specific, including whether your coral are colonies or just frags. For instance, I think it's tougher to color up some of the old school smothies in a higher nutrient system.
I think that on the whole, the older generation of reefers who have maintained the same tanks or tanks with the same live rock, continue to be able to run NSW and lower-nutrient systems without wiping out their SPS. I don't think that's coincidental.
If you are using things like GFO, carbon dosing and lanthanum to alter your nutrients nowadays, I think you're more likely to experience problems than you were in the past. I ran a slightly modified Zeo tank years ago, as well as a (non-Zeo) ULN tank, for instance. I can't get away with that today. In fact, years ago, I started a tank with Reef Crystals (which has a notoriously high Alk). However, today (literally today) if my Alk drifts above 7, my SPS' tips burn. My Alk shifted from 7 to 7.3 over the course of two days and I have burnt tips on an otherwise healthy PC Rainbow and a fledgling GC efflo frag, among others. Something changed somewhere along the way. I continue to believe dry rock versus live rock plays a role in what changed.