A spring loaded objective is as good as nosepiece focus. The disadvantage of nosepiece focus is complexity. The focus mechanism extends over a large part of the microscope. This leads to slop and play in the instrument. Stage focus is used by most manufacturers because it is easier to make, more direct and if properly engineered the stage is very stable.
Inverted microscopes use nosepiece focus for other reasons.
Inverteds are frequently used for micro-manipulation. The other problem with inverteds is stage size. Modern inverted microscopes have very big, heavy stages, nosepiece focus is easier to do. Most manufacturers focus mechanisms can drive the stage from the top of its travel to the bottom using only the fine focus. This is called infinite fine focus.