Think in terms of free cash flow, stock repurchases, and Iger's compensation package.
Since becoming CEO, Iger has spent
$9.8B in domestic and international theme park growth capex.
Meanwhile, over that same period, Iger has spent
$55.7B on stock repurchases.
Iger is reluctant to invest in theme parks because he'd rather spend company money on stock repurchases.
To understand why, you have to look at Disney's Proxy Statement to see how Iger's compensation is tied to 4 metrics, including "after-tax free cash flow", which is defined as:
cash provided by operations plus cash paid for restructuring costs and less investments in parks, resorts and other properties
In other words, spending on theme parks reduces Iger's compensation, but spending on stock repurchases does not.
Now, there's something called "return on invested capital", which sounds great for theme parks until you read this is defined as:
the aggregate segment operating income less corporate and unallocated shared expenses divided by average net assets invested in operations
In other words, the less Iger invests at the theme parks, the lower the denominator! Iger is better off pursuing low-capex schemes like My Disney Experience (whose capex component was relatively small), cabanas, special ticketed events, time shares, etc. Again, stock repurchases have no effect on this metric.
So, a lot of Iger's executive compensation is based on investing as little as possible at the theme parks.
Meanwhile, Iger's compensation
is based on EPS. Since a stock repurchase reduces the number of outstanding shares, Iger has a strong incentive to buy company stock. Put it all together, and Iger would rather drag out capex projects than build quickly.