It's crazy to think that Bitcoin needs Altcoins for survival. Do you realize that the price of Bitcoin would be MUCH higher if there wasn't any other side things that Bitcoin could be spent on[1]?
With the number of hacks and Bitcoin/Altcoin trading it's likely that the people on this forum lost large amounts of cash that could've been spent on Bitcoin[2].
The rich people don't really want to get involved with Bitcoin because there isn't any point to them in their point of view. They're kind of too old[3] so they just don't get it, it's beyond the similarity of the email service scenario from back in the days[4].
[1] Altcoin teams are spending tons of money on advertising. Anyone who has an altcoin would eventually have bitcoins. In other words, altcoins are the way for bitcoin to get advertised. There's not much advertisements about bitcoin, right? Only advertisements about bitcoin-related companies but not bitcoin itself.
[2] Supposed that there's no altcoin exchange sites, hackers would target bitcoin exchange sites instead and the number of bitcoins that would be lost because of that might even be larger because people's bitcoins are all in there. Unlike when there's altcoin exchanges, some of their money is on bitcoin exchange and some are in the altcoin exchange. Simply, altcoin exchange have actually saved some of our bitcoins somehow.
[3] Why are you thinking that all rich people are old? There are 16 year old kids nowadays that are richer than what we'll ever be.
[4] I actually think that rich people are more open-minded on things like this because they don't want to store all of their money on a single asset. Bitcoin is a good place to store some of your money.