So 50 years of NSL produced your list - let's see how many players 50 years of HAL will produce.
No doubt it will be a vastly bigger list.

Pretty much, for all the crap that's thrown at the NSL it essentially had 9 teams that were consistently viable until the end (Olympic, Sydney United, Marconi, South Melbourne, Melbourne Knights, Wollongong wolves, Brisbane Strikers, Adelaide City and Perth Glory) and the rest was a churn of different teams that fell over every few years (ironically Newcastle was consistently one of these), so what has really changed?

Positives:
Genuine professional league so players can make a career of it.
Greater market penetration that may pay dividends into the future.

Negatives:
Fewer teams and more foreigners (as we can actually pay them now) means that conservatively (if you assume that three out of five foreigners play each weekend compared to almost zero in the NSL) there's 70 less outfield positions for young players to potentially play in, meaning there's roughly half the opportunities for aussie players that there were in the NSL. That's not taking into consideration the places that are taken by reasonably accomplished players (Mooy, Milligan, Archie etc.) take that they wouldn't have in the past as it simply wasn't viable.Not getting those chances more often, younger could be part of why we aren't seeing as many of our youngsters going on with things.

I really think it's a bit of a mixed bag in terms of outcomes.