That's not entirely true. Each person gets a different amount of chances relative to their skill level, but the overall node has a much higher limit. So say player X has skill Y. He gets 5 whacks at the tree. This particular node hasn't been tapped yet and has 30 gatherings available. After you gather 5 times, you can't gather from that same location for five minutes.
Now say the above is the same, but you've gone back to this node 20 minutes later. It's still there, but now it only has 3 gatherings remaining. If you and another person are hitting at it, the first person to gather the last one will close the node. It will close on you mid-swing if this occurs. Given that there has to be several people gathering from the same location for this to occur, it is unlikely to happen very frequently. If you did, however, find a node that you particularly like the gains from, then it makes sense for you to camp one and wait the 5 minutes or whatever. In that case, it could be considered rude, but also a good indication that there is something there you might want as well.
WoW Blackhand-US-Date of Retirement: 9/21/2010... /Sigh
Devari - 90 Rogue 85 DK Druid/Mage/Warrior 70+
FFXI - Shiva "Retired.... Or not? One more try, honest."
Desmar - 65 Sam 36 Mnk 18 Thf 12 War
FFXIV - Devari Garamond - Sargatanas 50 Paladin / Culinarian / Weaver / Armorer
Beta - Devaria Ariadne - Ultros - Pugilist