I like to have plenty of disk space available to store whatever I want/need. As discussed, backups aren't really that big an issue since disk drive space is cheap enough today that an appropriately sized external drive can be used to perform backups.
A few years ago when hard drives were still super expensive, I remember having to backup to a tape drive because an external hdd was cost prohibitive. Not only that but USB and eSata didn't exist yet so an external drive was pretty rare.
1. Yes everyone does, For some people I think they don't really care about much space they have. Well in some ways they are a big issue depending on the situation you are in, For a business it can be crucial and maybe for someone who has a lot of personal data.
2. They certainly were, These hard drives are cheap as chips, You can portable ones very cheap and external ones too.