Even though he didn't have to worry about making more money Jake wanted to take advantage of the opportunities that came up before the 2000s there were still plenty of opportunities for Jake to make money from his future knowledge.
After 2000 they would also have plenty of opportunities, so he needed to have business talents near him to make the most of the fortune he would receive and invest, even though he knew that in more than 20 years Amazon's stock would appreciate, to become the company most valuable in the world didn't mean so much to investors.
After all, the company would not distribute its dividends to investors, so apart from selling Jake shares it could do nothing at this time of wealth, so even if he could not make that much money and invest in other companies he would need to earn something from it.
