That's the thing; there's literally no incentive for RBG to spend more. They invested in the stadium, they invested in big stars like TH14 and Rafa. Go back and look at highlight videos from the TH14 era. We bitch about attendance now, but from the eyeball test, it was much worse back then, even with the stars and the stadium. They cut down on big star spending and we still won 2 shields and were competitive enough. They also got brand exposure via Concacaf Champions League.
What would spending now do for them that wasn't accomplished by spending back then? There is no financial incentive to winning an MLS Cup. I don't think the league generates enough broadcast revenue for the team to say "you know what, let me drop an extra $10M on transfer fees so that I can win MLS Cup", because at the end of the day - they will just be out those $10M. It's pretty clear that their focus now is to go full Salzburg - get young, cheap players, and flip them for a profit. Not to buy a $10M young South American player to flip. Certainly not to buy a 30+ year old international player so that we can win a cup.
The problem seems to be that people are conflating "Red Bull" the global brand, and "Red Bull New York". Yes $10M is a rounding error to "Red Bull" the global brand, but in the real world, it doesn't work that way. "Red Bull New York" has its own budgets, targets, metrics, etc. to hit. And $10M is in fact a big deal for them. If the $10M won't get them a financial return, they won't spend it just to placate our dwindling fan base.
I agree with most of your post, except the stars thing. If the Red Bulls signed Ibrahimovic people would show up, like they did last year in the game against the Galaxy. If they signed Chicharito, people would show up. Soccer has gotten a little more mainstream here since Henry was around.
Also how does it change things if nobody shows up to the games? By nobody I mean Chivas USA-style crowds, which is where the club is heading in terms of their overall strategy and marketing. The attendance has been getting worse, despite whatever fake numbers the front office puts out.
No casual is going to be drawn to Red Bull Arena to watch college-aged scrubs like Stroud and Tolkin, especially in this market. You can rave about these guys all you want -- and they deserve their chances -- but at the end of the day they are unknowns who have no marketing value at all.
Barely anybody watches on TV already. MSG's local ratings must be miniscule.
So what does the exposure get for Red Bull if in the near future, people are no longer looking at it?