High 70s isn't hot to me, either, when outside. But other than in my childhood home without a/c it is never that warm inside. And never had it been that warm inside on a cruise ship before. Like I said, it wasn't a deal breaker for us, but it made it a little less enjoyable for us and it made our stay at the alchemy bar shorter than usual every night.
I just want people to be aware especially if they are sensitive to the inside heat.