It's got a frustrating "not fun" on-boarding. ie. the number of minutes from downloading "Julia" to getting cool satisfying results
1. It not a calculator on steroids like Matlab. It doesn't have one main open source IDE like Octave/Rstudio that you can drop in and play around in (see plots docs repl workspace)
2. The default language is more like a "proper programming language". To even make a basic plot you need to import one of a dozen plotting libraries (which requires learning how libraries and importing works - boring ..) and how is someone just getting started to decide which one..? I don't need that analysis paralysis when I'm just getting started
3. Documentation .. Well it's very hard to compete with Matlab here - but the website is not as confidence inducing. The landing page is a wall of text: https://docs.julialang.org/en/v1/ Tbh, from the subsequent manual listing it's not even clear it's a math-focused programming language . It's talking about constructors, data types, ffi, stack traces, networking etc etc.