I recently completed my PPL in Florida and all of my solo circuits were full stop and taxi back. I was told that this was a school policy due to the danger of students doing touch and gos and having/causing an accident. During dual flights and during my skills test it was mostly touch and gos though.
As a contrast, I also did training in Australia where solo touch and gos were the norm. This was on a significantly smaller runway with much more potential for something to go wrong in my opinion as runway could run out fast if you landed long. Still, at no point did I ever feel unsafe and I personally think non-first solo students should be allowed to practice touch and gos.