What aspects of Lotus Notes seemed like a good idea? Genuine question. I remember being horrified by almost everything about Lotus Notes. Sametime was great, though.
I realized how great Sametime was after I was forced to move to Skype for Business. The meeting functionality wasn't great but there were other great features. I sorely miss the button that allowed you to drag a rectangle on your screen and it would automatically send the resulting screen capture as a message. Not as an attachment that you had to open up, an actual image in the chat. Why can't skype figure that out!?
1 - Document Store (iirc, CouchDB was inspired by Notes/Domino)
2 - Replication - even past the 90s, it was one of the best tools for disconnected users
3 - Low barrier to application creation (it was about as easy as building something in Filemaker Pro)
4 - Easy publication of applications to the web (this was BEFORE 2000, so kind of a big deal back then)
5 - Administration of servers was pretty easy
6 - LotusScript (similar to vba) let you go much further than the prebuilt formula language (if you were willing to learn it)
Keep in mind, these benefits were available pre-2000, and in that time many were strong competitive advantages.