The way the feature was requested, come across as a dick move and very self entitled. The least the parent could have done is added some niceties or some reasoning in more than 4 words when asking something for free.
I know, people make the "I'd use it but for this feature" comment all the time. But I believe they do it without thinking rather than with the intent of being unkind. The "... pull request" is almost certainly knowingly mean spirited. (Even if true.)
Edit: here's a possibly better response than the "do it yourself" response:
XXX is a free and open source project. That means the developers put in the majority of their time on the issues that they want and enjoy coding the most, even if other good features are left out. If you're unable to help out with coding yourself, you could look through the open and closed issues and see of others have thought about your feature request too. If an open issue exists, a short "while I don't have the ability to code this, I'd like this feature too," added to the list would let the developers gauge interest and may sway someone into giving it a try. Thanks.
Edit 2: It's a bit long. This sentiment but shorter.
