The article is a bit disingenuous.

Steve’s main claim to fame was Apple 2.0 when he brought the company back from the brink of bankruptcy. He had almost no choice but to take radical bet-the-farm bets as the status quo was the company goes bankrupt.

Tim Cook inherited a company on an upward trajectory and kept it going. His core job was don’t $&@? it up, and at that he was very successful. Was Apple potentially less innovative during his tenure? Yeah probably, but it was stable and grew massively under his oversight, which was the job. Most shareholders that held their stock after Steve left are very happy with their returns since then.