Yes, they were experienced mountaineers. That is how they were able to identify the location of their snow caves to rescuers, why they left detailed notes of their itinerary posted in their car at the trailhead, and why they got along as far as they did. Their intended plan was to pack light, travel quickly, and make the ascent and descent as rapidly as possible.
Their fatal flaw was trying to predict Mother Nature and her actions. Blizzard conditions can be encountered on Mount Hood in the middle of the summer. An array of garments, sleeping bags, food, fuel, water, flashlights, and medical supplies should be available under the most ideal conditions...nevermind in the middle of the winter. These men gambled and they unfortunately lost. I hope we've learned lessons from their actions.
~ Blue Jays ~
Wasn't the weather forcast calling for a storm with 80-90 mph winds at surface level at the precise time they were up there?