a one TB drive is one medium - one single object which can be lost broken, stolen, etc. What if you only want to backup your 20GB of music? And then you want to backup all your photos (would take me two disks). Then what if you want to bring the pictures with you but leave the rest? Lightweight, portable, come on, there is always room for both storage technologies.
Now if all you are doing is incremental backups day after day, obviously a HDD is the way to go.
What irritates me is that if you don't want 1TB but only say 200GB, the drive isn't 1/5 the cost, it's like 3/5. (I know it wouldn't be exactly 1/5 because of overhead, component cost, etc.) My need is to backup family digital photo album. I predict it will grow to about 1TB by the time my kid(s) are adults. What do I back that up with that I can trust? I dont want to keep buying a new HDD every 3 years just to be safe, especially since my current boot drive is a 32GB SDD with room to spare after music and apps.
We need RELIABLE long term storage Maybe it's time to start storing less, throwing out more digital photos, movies, etc.