Carved one about three weeks ago--it lasted about 10 days before really getting rotten (getting lit every night). That just gave us an opportunity to carve another one.
Who cares if the first one rots? It is fun to carve pumpkins.
This has been my experience as well, carved pumpkins last much longer than just a few days. I usually carve mine a week before halloween and put them outside with the rest of the decorations (guess what I'm doing tomorrow

) and they still look good for halloween. I light candles in them only on halloween day.
Maybe it's regional weather? Around here average temperature in October is 50
oF.
And maybe the most obvious question of all: Why do we carve pumpkins at Halloween? (My dad did when I was a kid, but no one in my family likes pumpkin or cares to do it)
Because it's a fun, creative project that the whole family can enjoy doing together. It goes hand-in-hand with picking out the costumes and decorating the lawn. Tradition!

. . . oh, yeah, and them yummy pumpkin seeds!
Soooooo many fond memories of pumpkin carving when the DDs were younger. Before they could handle the utensils they would draw what they wanted and LDH would do the carving . . . this is the first year in 20+ that I'm carving a pumpkin by myself.