For Standard Games it’s mostly because of SS-Panzergrenadiers.
For the cost of an MG42 you can have two SS-PGs.
- Each SS-PG has +1/+1 defence and is two units, making them much more difficult to destroy.
- The SS-PGs have the same firepower vs soldiers at short and medium ranges.
- In most games I’ve found that you rarely make long-ranged attacks, meaning the SS-PGs are missing out on that.
- Additionally, instead of the LR attack they get Close Assault 7 and Ruthless
- I don’t know about anyone else, but I’ve never used Suppressive Fire, or even used the threat of suppressive fire (since they can defencive fire twice normally anyway).
- The MG42 does have 3/3/2 anti-vehicle dice, and while it’s not usually too significant it can occasionally be useful.
Now compared to some other units:
vs Sniper; the Sniper only has one shot, but gains some great abilities like Head Shot and Superior Camoflauge. Also except for point blank (ie short) range, the sniper generally has a better attack%, and Crack Shot cancels out the penalty for shooting at aircraft.
vs Nebelwerfer; the Nebelwerfer may only have one shot, but gets Blast, Bombardment, and Rocket Salvo. It also works out as having a better attack.
The MG42 can still be quite useful (eg you can pack 2 of them into a single hex for a LOT of firepower) its just that other units for a similar cost have more utility to them (Sniper), or are tougher (SS-PGs).