[1] Pick a dictionary and you will find references to lower-classes, the not-elite or the common people. https://www.merriam-webster.com/dictionary/the%20masses https://en.wiktionary.org/wiki/masses#English https://www.vocabulary.com/dictionary/masses
[2] Put in to words nicely here https://medium.com/@steve.yegge/why-i-left-google-to-join-gr..., but you can feel it in many of Google's products where they make all the major decisions because they don't believe users are as capable of making good decisions as Googlers.
And then, of course, nobody said you're part of those masses anyway. Maybe you're not. Do you enjoy Google product X as other hundreds of million do? Then you're part of the mass that enjoys it. Otherwise you are part of the mass that doesn't.
People do sometimes seem to forget this! - so it's good to have a reminder.