The fishermen in the boat, the Ocean Challenger, died because they were not able to don their lifesuits quick enough. Why don't these men wear lifesuits before they embark?

The Ocean Challenger sunk off the coast of Alaska in 2006.

http://deadliestreports.wordpress.com/2007/03/31/at-the-start-of-king-crab-season-a-vessel-went-down/

Alaska's State safety and equipment requirements are identical to the U.S. Coast Guard (USCG) federal requirements, with one additional rule.

The Federal Regulations dictate that:
All recreational boats must carry one wearable PFD (Type I, II, III or Type V PFD) for each person aboard. A Type V PFD provides performance of either a Type I, II, or III PFD (as marked on its label) and must be used according to the label requirements. Any boat 16 feet or longer (except canoes and kayaks) must also carry one throwable PFD (Type IV PFD).

PFDs must be
- Coast Guard approved,
- in good and serviceable condition, and
- the appropriate size for the intended user.

Accessibility
- Wearable PFDs must be readily accessible.
- You must be able to put them on in a reasonable amount of time in an emergency (vessel sinking, on fire, etc.).
- They should not be stowed in plastic bags, in locked or closed compartments or have other gear stowed on top of them.
- The best PFD is the one you will wear.
- Though not required, a PFD should be worn at all times when the vessel is underway. A wearable PFD can save your life, but only if you wear it.
- Throwable devices must be immediately available for use.

https://uscgboating.org/recreational-boaters/life-jacket-wear-wearing-your-life-jacket.php
helium.com/items/1304062-alaska-life-jacket-laws-alaska-pfd-laws-alaska-boating-safety no longer exists

A fisherman can't do his job if he's wearing a Gumby suit. They are stored for emergency use. Pix here:

http://psc.apl.washington.edu/HLD/CBL/Teacher/Webcode/August3_update.html

The neoprene kind the boat had are too restrictive to work in. No fishing crew works in full immersion suits. They do have partial suits that they can work in, but they'd still have to don a PFD in an emergency, so why not just don the suit.

In the case of the Ocean Challenger, it was apparently hit by a rogue wave that rolled it during the storm...the crew scrambled to get the life raft overboard, but were tossed from the boat by another 30 foot wave. I can see why the others might go for the life raft first, then don the suits once in it, since a survival suit only lenghtens your survival time in the water by hours, whereas a life raft would provide a longer survival time in an open sea. And it'd be hard to launch the raft if you were in the suit first.
You don't think about rogue waves, it's like flying and hitting an air pocket, it's not high odds, and almost always the vessel recovers from one, it just rolls and rights itself. The Ocean Challenger was not a crabber or pot boat either, so it wouldn't be top heavy or prone to capsizing. They were just in the wrong place at the wrong time.

The rescue of the survivor:
http://www.youtube.com/watch?v=GEu_oymX6iU

A rogue wave hitting another fishing boat:
http://www.youtube.com/watch?v=l_8hOai9hGQ