I am an average airline pilot of average ability - no more experienced than the fated Captain on the Helios, and possibly less. He had issues. The pressurisation controller on 737s is far from perfect - but then none are - as with all systems, vigilance and proper procedure would have prevented this accident. We shouldn't be so hard on Mr Boeing.
I think most of us are not complaining about the pressurisation controller which indeed is still being fittet to brand new 737s today (700s that is) but more about the warning system. Yup, i did fly the airplane in question for several years before it went to Helios and had to cope with the problems or pitfalls of the pressurisation system as well, im glad i never had any pressurisation event although a few colleagues in my company did. We still use the same warning system, the only thing boeing has changed is two additional lights that tells you which kind of warning you hear which apparently makes it fool proof as boeing does not require any briefing to the different actions when we hear that sound either in the air or on the ground when those warning lights are installed and operating.
That said, we have to cut Mr. Boeing some slack, after all the aircraft and warning system design is after all over 40 years old by now and should be very well known by all pilots operating this thing, if they are properly trained of course.