They just make a platform that really hopes it will be used by people around the world without creating tokens to attract investors early in the journey
But they don't just hope, do they? It takes a looot of investments to make a certain brand recognizable, attract an audience and convince them to use it, and without that - no investors will give their money to your project. So, funny enough, but if your platform isn't really unique - in order to draw investor's attention you already have to be something, and not everyone has sufficient funds for that. And years ago it was way easier than now! Nowadays, due to enormous competition, you'll have to invest even more.
And the other way to attract funding - is being unique, so that your company won't have many analogs in the market, and one of the easiest ways to do it - is to associate your project with something new - altcoin, convince investors that it's something extraordinary, explain why it is better than other existing alts and voilà - your project has just become interesting. It's another matter that nowadays there's such a wide range of altcoins, that even this method isn't working much, but it doesn't require many funds, so..worth a try.