I believe that before the 'skip the line options' Disney was considered a worthwhile visit. I don't remember as a child people complaining that it was unfair if they chose to get there late that they couldn't get on everything, it was just accepted that was the way it was an you planned accordingly. If you only could last 5 hours then you did what you could in those 5 hours. Obviously if a 'cheat' is brought in to give you an advantage free or not, some are going to love it and choose to use it. The knock on effect is that those not using the 'cheat' will have to wait longer as others get an advantage over them. Whether that suits those using the 'cheat' depends on the cost, the effectiveness and the availability of that system.
I used to love using the free Fastpass system. I did however accept that for those unaware of it that it had a negative knock on affect to their waiting time. I'll accept that it was sort of selfish of me using it, but then I figured it's there and free for everyone to use. Now in effect you're paying for the same thing with Genie+. It can't be denied that affects others, again it's up to folks to decide whether they want to use it or not.
So I say it's sad because with free fastpasses, I think more people were happier. To use your own words 'the fact that people feel the need to buy it in order to make their vacation worthwhile' is more likely now that Genie+ exists. People are told "You won't ride without Genie+ or will wait 2 hours per big ride" on here makes them more likely to buy it. The fairest method is certainly no 'cheat the line system' but not everyone agrees depending on their circumstances