I get what you mean ddm – I just think of it as feel rather than a soul as such.
When choosing my last bike I initially went for one based on reviews & perception, tested it & hated it. Then another, then another so ended up riding all sorts of bikes over the next few months. Several were good, a couple very good & one just made me want to ride it again & again. It was a simpler design than most, not particularly nice to look at but it felt like it was made for me.
Even now, 5 years on, IMHO, it still rides better than anything else I’ve tried (despite having small wheels, not enough travel & too many gears). 🙂