yeah.. totally agree..

anything complex expressive, or naturally entwined with 'human' sounds..
like harmonica and flute..

and most 'plucked' strings

can sound quite dire on most basic
'home keyboard/cheap soundcard' general midi soundsets..

and not entirely convincing on the better most expensive
mega gigabit 'pro' sample collections..

but.. there are still technological advances to be made..

and even now 'movie sountrack' composers employ state of the art
orchestral sample sounds
most audiences would not be able to distinguish..

maybe even many classical music buffs mighrt be surprised how often
they have not reaslised what they were actually listening to..