Excellent idea. Jagex has done a few things to RuneScape gold adress this, but it doesn't really work for veteran players. These include quests. I went there to find the quest, much as I did in the desert or Morytania. This is the main reason why you should visit these areas, but the problem is that once you're done there, you're done.
Slayer. This can tie you to a fight, and the point is that you go to these locations to fight. Unfortunately, many slayers are trapped in the dungeons. However, certain areas are open to all. It's impossible to run through an area with an aberrant or spectre without the proper gear.
Hunter. Jagex added this skill because it allowed people to use peaceful areas. To catch Chinchompas or Kebbits (until BurthoTav) it was necessary to venture out into nature. It was a fantastic method of encouraging people to leave civilisation. Fishing, in f2p. You had to go to Karamja to get the best fishing. True in members for the living rock caverns.
Woodcutting. Mahoganies and Teaks were/are very uncommon jungle trees. Unless they add many unique resources to every single map What do you suggest they can do? Most resources have to be implemented with care for any value: Mahogany needed to learn the art of construction, some hunter regions required summoning and so on.
I do think that the map could be a little bigger (personally I'd love to see more small villages and so on with lots of farmland, might be helpful for quests). With more land, Jagex has more to work with. My impression of the proximity to Varrock Edgeville, Gunnarsgrunn, and Varrock (a more appropriate name than Barbarian Village, but buy OSRS gold I don't like the term barbarian when it's not properly used) is not true.