Ultimately we can't work on even a fraction of the features that every person wants, and Laurie said his idea was simple to implement... so why not show how it's done? Honestly, it's not that sinister and it is certainly not rude.
But let's look at the Tweet in question:
"@lclarkmichalek @weavenetwork please, if it is so simple and robust you are very welcome to contribute a patch."
1. He says "please", which in this case is sarcastic.
2. Then he says "if it is so simple," which is a dismissive way of saying "you think that it's simple, but you're wrong – it's actually very complicated."
3. And also "if it so so ... robust," which is a dismissive way of saying "you think that it's (more) robust, but you're wrong – it isn't."
4. And finally "you are very welcome to contribute a patch," which, first, does not need to be said as presumably anybody knows that they are welcome to submit a patch to an open source project, and second, basically amounts to "so, I'm going to make my problem your problem."
This case is different from a feature request from a user, where "feel free to do it yourself" is slightly less inappropriate. There, what is meant is "this feature is not important enough to warrant our endorsement or any allocation of resources, but if you were to take on the burden entirely yourself, we would consider it."
In this case, what is meant is something more like "we believe that your charge that there is a fundamental issue with our software is false and we are not interested in discussing until you have actually done the work for us," or in other words "fuck you."
I admit, "fuck you" is quite strong for the general case, but the tone of the Tweet warrants that translation.
For what it's worth I lean more to the uncharitable reading of the tweet, although I'm not as firm about that reading as others appear to be.
Tweets for communication are hard so it's not particularly suprising when what you say and what you think you say doesn't match what other people think you said.
Just admit that you (if you're the one who wrote that response; it's not exactly clear who's who in this discussion...) were being a bit of a twit and move on. We all do it; I do it, the girl next door does it, my grandma even does it and she's the nicest person I know. There's no shame in being honest about it.
Typically (at least in American English vernacular), "please" is very frequently used in a sarcastic manner (e.g. "You think you can jump from the top of that building and not get hurt? Bitch, please." or "Oh please, like you know the difference between a grape and a grapefruit."). While this sarcastic usage is usually accompanied by some other word prefixing it ("Oh please" or "Bitch please" or "Nigga please" or somesuch), it's not uncommon to see a lone "please" used in this sense as well, and the tweet in question very closely resembled that usage.
It was actually @lclarkmichalek who ended the conversation.