>Why does everything have to make money? People like to built things as a hobby.

The gp asked a reasonable question. Your admonition about making money is misplaced because your assumption about it being a hobby is incorrect.

The website was developed by Flighty LLC. To answer the gp's question: Although the website itself doesn't have direct monetization, it acts as "inbound marketing" for the paid iOS app. Clicking on "Download Flighty" takes the user to the Apple App Store:

  In-App Purchases
  Week-to-Week Flighty Pro         $4.99
  Annual Savings Flighty Pro      $59.99
  Month-to-Month Flighty Pro       $9.99
  Annual Savings (Family Plan)   $119.00
  Lifetime Flighty Pro           $299.00
  Flexible Monthly (Family Plan)  $15.99
  Week-to-Week Flighty Pro         $4.99
  Week-to-Week Flighty Pro         $7.99
  Pro Family Lifetime            $449.00
  Annual Savings Flighty Pro      $59.99

The website's hyperlink url to the App Store page also has a tracking id so the company can attribute downloads/sales back to the webpage. This lets them see how well the "free website" is converting to paid customers. As a vehicle to generate sales leads, it seems to work very well. To wit... Wikipedia says the company has been in business for 7 years and it's been upvoted to the HN front page and we're discussing it. (The Flighty website is an example of the old saying, "The best advertising is free advertising.")

It's not just a $5/month VPS. Some cursory googling says Flighty gets data from the FlightAware Firehose api which costs a lot of money. The cost would exceed the financial resources of most people to make an equivalent free hobby website. (https://www.flightaware.com/commercial/firehose/documentatio...)

Flighty Airports