The people who wrote and produced the TOS films were feature film makers and scriptwriters to begin with.
The people who produced teh TNG films were TV episode production people and scriptwriters - and it showed (in a VERY bad way.)
With HD TV (and 16:9 framing and higer picture resolution); the line today is getting blurred; but when the TNG films were made - the distictopn was very clear.
Nemesis suffered from two things - John Logan being an AWFUL scriptwriter (yes, he made his feature film name with 'Gladiator'; BUT the script work he did for that film was HEAVILY reworked and rewritten before it was filmed - his name stayed per WGA rules); and Nenesis shows what John Logan is capable of on his own (and Brent Spiner being 'in' on the script didn't help.)
but in't the difference between having an actual feature film crew VS a TV episode production crew - the mindsets are VERY different.