This non sequitur annoys me. Deconstructing it:
* A: "Matz is nice": Let's say we all agree this is true.
* B: "we are nice": i.e., the ruby community is nice.
* P(A -> B): (A therefore B) is a slogan, so I assume the proposition P is believed to be true. Is it?
In order for P to be true, the only option is for B to be true as long as Matz keeps being nice. Assuming Matz is still good-natured, is not hard to find counterexamples for B (every big community have some less-than-nice people). So the facts tell us that P is false.
Alternatively, if you assume that Matz is not nice, then, without mattering if "we" are nice or not, the slogan holds true (modus ponens [1]).
Anyway, my point is that the slogan is as silly as this rant :p.
1: http://en.wikipedia.org/wiki/Modus_ponens#Justification_via_...