Below is a copy of an e-mail I sent to the ISC in response to a claim that orphaned open source projects display the dark side of open source:

These dangers are not specific to open-source. For example a copy paste from the article with the words 'open source' removed still rings true:

"This is the downside of software. What happens to it when the original maintainers tire of it, move on to other things, get hit by the proverbial bus,...?"

You need to evaluate the project team around a software product whether it is open source or proprietary.

If anything this is a positive of open source; The original project team went dead, but you still have security patches regularly being released, something unlikely to happen if a proprietary product's company went under.

UPDATE: added 'Below is' to first sentence.