Why do you think that large investors will not invest in altcoins? I think that if Bitcoin develops, then most of the altcoins will develop.
Because big investors are not going to care for a coin that no one knows and that no one trust, they will want to get in bitcoin because even if the profits that bitcoin gives seems low for people in this market the profits are incredible compared to other markets, so why take a chance with those useless coins when you can buy the best one for cheap and wait for the rest of society to realize the big mistake they have done by ignoring the technology that will change our futures.