This is a general forum about FFXI, not a general general chat forum.
Yes, the subject is supposed to be related to FFXI - and granted, the OP was stretching this a bit. The OP was referring to use of recreation time on a holiday weekend (as it is a 3 day weekend for many here in the US). As FFXI is a recreation that many US players may be choosing to take part in with their extra free time, it is related to FFXI in this way.

Basically, the OP could have been saying was "Hey US players, if you use this forum, it is likely you will be using the 3 day weekend to play FFXI. While doing so, please remember the reasons you get that extra day off."

Again, the wording could have been more specific, but it is related in that way.