There's plenty of 'different' maps out there, but people simply don't want to play them...
There aren't plenty of different maps, there are quality maps and then there are one sided sub-par maps with issues preventing them from being played in any larger scale.
Tanteville - Single front map, no/very limited cover for infantry.
Bocage - No open areas around the middle, too many chokepoints means artillery spam fest
D-day - No open areas around the middle, too many chokepoints
Egletons - No way to turn off snowfall (should be optional weather), cars block pathing on roads, not enough cover for infantry
Falaise - Single front map, pathfinding issues near the middle
Abbeville - Single front map, too many chokepoints on the right side of the map, otherwise good map
6P_FRANCE1944 - Limited movement because of heightmap issues in the middle and randomly placed hedges on the right side
Adaire - Too cluttered/limited movement or pathfinding issues
Chateau - Big area around the middle tends to create a single front, otherwise good map
St Come Du Mont - Excess amount of hedges, especially close to spawn area, otherwise good map
Monte Cassino - I think people just dislike the big trench in the middle, it tends to get a bit stale, otherwise good map
Aside from the three last maps and Abbeville, they all have issues that break the flow of gameplay or creates imbalance. It's not fun to lose just because you played a really one sided map with no variation that caters to specific company or a map where it's impossible to advance past a specific point.
Then there are maps that are so bad that you can't play them at all. Like radiostation and graveyard, they are basically just one big open field. Very far from relic quality.
Problem is if its not skaffa certified no one touches it, because it forces them to adjust and people are lazy
You can't adjust to maps since you don't know beforehand which map it's going to be.
Having the launcher select the map before the game starts so that everyone is prepared to play on the map would improve a variation in maps being played but arguably it would just create games where the team who exploits the map the most wins, since most maps are extremely linear.