MUMPS’ bad reputation is totally unearned. Most examples online (the wiki page, the awful Case of the MUMPS article) are examples of MUMPS code from the 60s-70s when storage was a premium and enterprise-size programs had to fit in a handful of megabytes, so there was no room for readability.
MUMPS code is more readable than most languages, it’s very simple and procedural. And the ability to interact directly with durable data the same as you do local data is very nice. I don’t know why no modern languages try to do something similar.
Interacting with durable data storage is actually pretty common.
Perl is modern (-ish? Definitely modern compared to MUMPS) and had "tie" for database access forever [0]
Python's dbm interface also looks like a regular dict [1]. I am sure there are many others, I know we had one "magic dict" in one of my work projects.
It's just that transparent access has some limitations, like lack of transactions, unexpected latency, lack of strong types, inability to only change a single value.
You would love OpenEdge ABL.
ABL is structurally much closer to Oracle PL/SQL than to MUMPS.