A similar story with Gus. He was also planned to be introduced briefly, but Giancarlo Esposito's charisma won over the American audience, and he was given more screen time. In general, the entire series was built on the principle: "we threw together some exposition, and we'll figure out what happens next during the season."
They filmed a ton of stuff, then abandoned a number of ideas. There was even a scene where Walter essentially rapes Skyler, as there were too many negative letters addressed to the character and even the actress. But then they thought it over and decided not to make Walter too much of a scumbag. In short, times were a bit different, and the approach to filming content was too.

