Look, yes, you did wildly miss the mark. But I respect you owning that.
I think the MuseScore video is reasonably good reference for doing that sort of critique right. I'd gently point out two things. One, the MS video takes time to first explain what good UX is and why it's good, gently winning the viewer over with positive examples. Then it contrasts MS against best practice, relying on that earlier set-up work to ensure the viewer can follow along and see how MS is not quite hitting that mark. Two, it never denigrates MS; instead, it repeatedly affirms the author's enthusiasm for the product. It comes across as fairly compassionate and constructive criticism. Your piece, irrespective of its intent, didn't come off that way.
If you do want to do more criticism in the future, the MS video is a good point of reference. But I would hasten to add that good criticism is genuinely very hard. It takes work to do it right. It's not enough to simply be compassionate, you also have to demonstrate that compassion by weaving it into the final work of criticism. It must be a constant thread from start to finish, not a box one ticks off at the start or end.
A second option is to avoid criticism as such. Your piece could have easily been reframed as 'Mac emulation is really cool, built by these absolute legends, but none of these tools are quite right for me, so I made this fork that scratches my itches, and you might like it too!'. It gets the exact same points across, but does so much more gently.
That's not to say there isn't, at times, place for criticism strictu sensu. There is. But criticism is most effective when it is most constructive. Less cathartic, maybe, but catharsis at the expense of others is hardly something to aspire to.
I've taken the time to browse some more of your site and I think there's some really cool stuff on there. Don't be discouraged, or fall into the trap of being defensive, you have worthwhile things to say. Just do it with the same thought, patience, and compassion you'd want others to extend to you.