Not much motivation to explore. I thought getting bored with your current location was always a great motivator for exploration.
"I'm bored with these plains. I'm going to go and find some more plains." Is that what you mean? Pre-1.8 I could have understood you saying this - the terrain looked so different everywhere that moving on into another area which was the same biome type would have looked completely different. As it is now, you have the choice of 3 biomes that have trees, one biome that has mountains and the other biomes which have a whole heap of nothing.
Well that's excellent for you. However, I and many in this thread haven't found landscape that we found interesting.
I could see where you were coming from if people only played Minecraft to build megastructures. However, many people like to explore. I find a nice place, build a tiny house and keep exploring. Minecraft stops being fun when exploration just finds you blank canvases - mountains that you have to plant trees on or huge plains that you have to build on.
I don't really know who you're talking to here: very few people have been complaining about a lack (or abundance) of building materials - when we say that there aren't trees, we aren't saying "there's not enough wood to build a nordic city", we're saying there aren't enough trees. Trees on mountains. Or valleys. Or anything that isn't a flat plateau.
Yes, this is exactly what everyone's been complaining about! Everyone here's been saying "guys, we all play this solely to build things; so don't you wish there were more materials to build with".
I have a suggestion for you: download the flat terrain map and go into creative mode. All the resources you could want and none of those unsightly hills and trees to get in your way.
I normally don't like to respond like this, but you seem to have missed the point so badly that I just couldn't stop myself.