I think the largest group that will watch live coverage in the next 10 years aren't either the regular disc golfers (who may be out playing a round instead) or the totally non-disc-golfers (who really don't know what they're watching). I think it's people who have heard about it, maybe they have friends or co-workers that play, and they've tried it once or twice.
Go out the first couple of times and try to throw a disc far, probably a high speed driver, and see how it dumps quickly into the ground. Then go watch a YouTube video of pros. HOLY ****, you can do THAT with a disc?!?
I remember being in awe when I first started watching tourney's online. Made me want to get out and play again, get better, and throw (roughly) like the people I was watching. Which made me want to watch more. Then as I got better, it just made me appreciate even MORE how good those guys are. It's been like that in every sport for me. If I play it, I want to watch it, because I can see and understand the nuance and appreciate the really good plays.
I think what you're saying is that feeling fades over time. Either the "awe" factor gets stale and you stop watching, or you get into the sport enough that you'd rather be out playing (when talking about live streams). Maybe you've moved on to where a highlight reel would be up your alley, instead of watching a whole round, where you get to watch and appreciate an 1100 rated round in rapid succession, or Eagle/Simon/McBeast bombs or Ricky's lights-out putting or whatever (recap videos?).
So then you need a revolving door of newer players discovering the sport, discovering the live coverage, and wanting to watch it. That's growth. We need sustained growth to support that.
Otherwise, it's the elderly. 100% conjecture here, but I'd bet there's a large portion of the BG watching population that's in retirement. A) they have the time to watch, B) they can't physically participate anymore. Both driving them to be TV and on-site spectators. You can still appreciate the sport without playing it anymore. We haven't reached this stage in DG yet, numbers wise. With the ever-growing participation, we'll see ever-growing age protected divisions, and with that increase down the road, comes a larger group of people who have the time and desire to watch the sport, but not necessarily keep playing it as often as they did in their youth.
To summarize, we need continued growth to drive new players to discover the sport and its coverage, in combination with elderly/EX players who have the time but not the physical prowess to get out and play as often and still want to keep up with the professional scene. I think both of those populations are currently growing. Is there a breaking point #'s wise in their growth where it starts to make financial sense for live coverage? No idea where that is, but I'll second the notion that the continued progress of all the DG media groups is really impressive, and is making great strides towards setting us up to be prepared for an influx of $$/sponsors/advertisement.
Personally, I watch every post-produced round I can. I try to hold off to watch them with my wife when possible, but life gets in the way quite often and with all the multiple card coverage of so many great events we have now, it's actually hard to keep up! (I'm also like 400 movies and 25 TV shows behind...). I play DG as often as I can practically find the time for, and I'd LOVE to watch any live coverage I could...but, ya know, real life responsibilities always have other things in mind.