Can you be specific and state what skills you are referring to?
How so? The main difference that I've seen from classes way back vs now is stress factors (sometimes referred to as harrassment) were added in order to "teach" people to hold themselves together if something was to go wrong. Swimming skills were emphasized more so than what I see today.
Can't say I agree with this, yet don't entirely disagree. PADI and NAUI's open water course is designed to create an autonomous diver who can plan a dive and execute the plan safely. What I've noticed, and this is the way I was taught, is the students were required to learn the skill conducting it once maybe twice in the pool, then do it again at the lake/sea. After the last dive my instructor told the group "congrats, you now have the certification to go out and learn how to dive" My thought was 'what?', I just paid for a course to learn how to dive and now he was saying I didn't learn how to dive. I didn't understand his comment until I became an instructor and learned how courses were set up. That is, a student is taught the needed skills and must demonstrate he/she can conduct the skill during the certification dives. After that, it is up to the student to go out and master the skill by practicing and diving more. The later statement really stuck out to me when I took my first PSD course.
This of course, brings up the other issue, many people don't take the time to practice their skills. They just want to flop around with the fish. The more serious, perhaps those who thoroughly enjoy diving, practice our skills, take more classes, dive often as possible, move onto more challenging diving such as tech, and for some gripe how courses have been watered down.