It's still good, but died because no one understood it
Everyone loves to hate Lotus Notes because it's a crap and bloated email program.
And that's the problem right there - it's not an email program.
It's a workflow program that can do email. And it does workflow really well and fast. Used a non-relational database yonks before they became popular. Never had the Y2K problem. Did foreign characters natively before Unicode existed.
A common problem with trying to get rid of it is : "Yes, we can replace that with Java-Oracle using Spring for £500K" "But, but it only cost £80K to start with and £40K in maintenance since!" The answer is of course, to phase out and close that division of the company so no one higher has to answer that question.