Why?, page-7

Remember that Sydney Airport Holdings (the parent company) has a lease on the airport till the end of the century.

So while debt is important, it's less significant for SYD because:

1. It's a monopoly.
2. The 99 year lease (from 2002)
3. You pay $6 for a coffee and $12 for a sandwhich and $15+ to park your car.

In normal times it prints money and returns approx 4.5% in dividends.

So in the short term it's speculative. But if you have a 5 year + hold strategy then it looks like good value. Air travel will return to normal, and it's better to get in now with a 5 in front of the price than a 7 or 8 in a years time.