I think it's more so your business travel experiences that caused you to hate it initially, not the solo travel itself. I've used similar rules, sometimes, and other times I didn't, both were good. For example, I stayed 5 weeks almost exclusively in Seoul last year and it was awesome, I met many people I simply would not have had I only stayed there two nights. I also discovered a lot more of the city and over the weeks I was able to feel myself living more like a local. Very interesting experience.