They want to grow the game in Italy and the road they're going down now is the best option IMO. Make the national team strong and have two strong representatives in the HEC and ML and with a bit of success it'll generate a good feeling towards rugby which will help to grow the game. They could have left things the way they were and hoped their league would eventually grow like the French league did but it took the French many decades to just win a 5 nations match.

Having 2 teams will also allow them play all their best players at a higher level and allow them set up academies.

The 2 Italian teams have gotten great crowds this season considering its their first season and especially considering they're near the bottom of the league. Crowds will grow once they become more competitive and new rugby fans will come along.