This turned into Mozilla, and Mozilla—based on the Netscape code base—was seen as bloated. So a project from the Mozilla team was launched to create a more lightweight browser. It was named Phoenix while in beta, and the plan was to name it Firebird. This conflicted with some other copyright out there so they named it Firefox. It seemed like an odd choice of name at the time.

And now Firefox is seen as bloated by many. History repeats itself I suppose.