I wantt to sum up some of my thoughts on why modern minecraft isn't as good as it could be, and I want to hear what others think as well.
And I think the place to start is with minecraft's survival mechanics. I don't believe modern minecraft really feels like a survival game anymore. In earlier versions the first night was a threat, if you didn't find shelter for that night you would likely be dead. Modern minecraft doesn't handle this as well because players can come across villages that have food, shelter, and beds to skip the night. Alternatively modern minecraft players can pretty easily find sheep and craft a bed on day one.
The next big difference is the food system. If you don't have any food in modern minecraft, it simply feels like an annoyance. It slows you down, you constantly have to keep eating, etc.
The beta 1.7.3 version is better in this regard because when you're low on food, the only risk is that you die. It doesn't make you move slower, it is simply a risk of death, and you aren't annoyed at a movement penalty, because your speed is always the same.
Then there is just the general difficulty. Maybe it was just because I played the game when I was younger, but in the past, nights felt dangerous, that you needed to find shelter and would not be able to survive in the open for very long. Modern minecraft kind of flips that and to a degree expects you to wander in the night for ender pearls. I really think that the night should serve as a threat, and that's where the old system works better.