I think it's because of a quirk of human psychology. The value of a product to us, as a user, is about how well it fits into our daily lives. "Fits into" is the operative phrase: to get adopted, a product needs to be nearly invisible, and fit into what we're already doing so well that it's just a seamless augmentation of our own capabilities. Such products naturally seem trivial.
By contrast, we judge the importance of a project by a combination of a.) how difficult it was to do and b.) how many people it affects. Both of these are anticorrelated with how likely it is to fit into our lives. Difficult projects are usually complex; that complexity tends to spill over into the user interface and make it harder for us to make sense of how we would use the product. (Indeed, when moonshots like Google or Tesla succeed, it's usually because they manage to put a complex problem behind a really simple & familiar interface.) And aiming to please a large audience means handling a lot of corner cases, which again bloats the user interface and makes it harder for any one person to adopt it.
Once you've got lots of happy people adopting the product, they can serve as teachers and evangelists to bring a little more complexity to the wider world. But if you build something designed to change the world from the start, it tends to "bounce off" of the world, as it doesn't actually fit into the daily needs of any one person.