Here's the unbiased truth
Goldberg had the look, and the ability to lift people over his head. When he was being booked as an unstoppable monster, that was all he needed. But you need more than that if you want true longevity in the wrestling business, and despite early signs that he was willing to learn, either someone got in his ear, or his own ego got to him, and he decided he didn't need to improve anymore, and he actually regressed around the time of WCW's collapse.
When he came out of retirement, he honestly still had a killer look (especially in an era of smaller wrestlers), so it made sense to go back to the well of booking him as an invincible spear/jackhammer merchant. But after that Lesnar match, WWE/Goldberg just couldn't let it go.
