Roger.
If ballistics had come with an increased TH or Critical chance, or a better range-paradigm (like lasers), or lesser mass right out of the gate (as in, 1984ish) they would seem to have a raison d'etre alongside directed-energy weapons. If missiles did more concentrated or reliable damage, they would seem to have a greater utility for the troopers out in the field. That would make them more realistic within the confines of the setting, and therefore less-primitive feeling.
Note that I am leaving the obvious adjuncts from those two broader fields (like MRMs, RLs, rifled cannons, 500-kilo machine guns, etc.) out of this because I believe those are a bit more universal in this consideration of primitiveness.
This all comes from someone who adores the AC/10 above nearly all. So, while it may not make absolute sense, it is still a viewpoint.