In my opinion it's not so much the case of analog sounding better, it's about the difference in tangibility when I use analog gear and the focus on sound rather than the music theory.

When writing using software I spend far more time thinking about the music theory. This usually leads to pretty sterile sounding (but musically good) pieces.

When I write using analog I focus more on the sounds and how they work together, spending hours tweaking knobs and faders. There are far more "happy little accidents" when doing this, most of which I couldn't imagine doing with software since they are not planned. I write much more interesting music using analog.

It's similar to playing a real guitar versus a software guitar synth, there are weird little quirks and surprises when playing a guitar that can't be emulated with software.