If the Mafia doesn't do business with a large gang such as the Bloods then they are leaving money on the table. In Philly, Scarfo and Stanfa did business with the black mob and Pagans motorcycle gangs. My guess is the Lucchese's found out about it and wanted a taste.

"When my time comes, tell me, will I stand up?"
Paulie "Walnuts" Gaultiere - The Sopranos