Here is Dave Parsons' official statement from the RF blog:
RunwayFinder will be shutting down at the end of February. It's been a great 7 years, but it's time to fold her up. While I understand AeroNav's need to re-capture costs, the new chart fees along with other licensing fees will put RunwayFinder firmly into the red. If this were the only issue, I could try collecting donations. However, the site needs continuous maintenance: the airport data format is changing this year, the weather gathering needs updates, and improvements are needed to keep up with the latest browsers and mobile devices. I've had many people suggest alternatives, but unfortunately there is no way to keep it going (for reasons I can't disclose).
When I started RunwayFinder in 2005, viewing aeronautical charts online was difficult. I was learning how to fly, and wanted to look at charts from across the country to dream about where I could fly some day. Being a software engineer, I wrote some code, collected a bunch of data and charts, and RunwayFinder was born. It made a little money along the way, all of which was plowed into legal defense. Despite that, it's been a fun project and a great learning experience. Thanks to all the pilots out there that used the site, and especially those that helped out along the way.
Sounds like a few issues are at hand, the primary one being that he is sick of working on it. I can't say I blame him. It's a hobby site and not his livelihood. If that was the case, perhaps things would be different. His reward is not worth the personal risk of being sued by FightPrep and its clones.
Re: the statement about the government becoming involved, that's a double edged sword. The government is the entity that records patents, and who gives the power to a company like FlightPrep to sue hobby operations out of business. The absolute greatest crime in this whole mess though is the discontinuation of sales of digital chart data to individuals, furthering the stranglehold of corporate products like those from FlightPrep. I could go on a long rant here about big business (not that FlightPrep qualifies) lobbying for a turn with your anus, but I've got to go occupy something.