It has been pretty clear that there was only going to be 1 area per planet in the Alpha and Beta, and if you thought that there would be more, you've been fooling yourself. Yes, there has been concept art of more, but nothing was ever 100% confirmed in the game and we never saw any game footage beyond Venus, Mars, Moon, Earth, Tower, Reef and Mercury ( which is still in the game as an arena for the 'Crucible elite' with exclusive rewards ).
Also, you gotta love how some people make assumptions on how the final game will play based on a level-capped Beta with areas we can't properly explore because they are guarded by Lv.?? enemies ( Grottos ), at least three fully blocked off areas ( Seraphim Vault, Jovian Complex, King's Vault ), limited gear ( only Common and Uncommon ) and not much use yet for some of the stuff you get due to the level cap ( Materials / Crucible / Vanguard Marks ).
There are legitimate criticisms and concerns, yes, but this jumping to conclusions and making assumptions needs to stop. People are talking like the relative lack of things to do in the Beta ( *cough* Level cap *cough* ) somehow will be this massive problem in the full game, but they forget that in the full game, you don't stop at level 8. The stuff we had available to us after hitting the cap in the Beta is not representative of the final game, because in the final game, the endgame doesn't start at level 8, it starts at level 20. The lack of stuff to do when you're capped at 8 in a Beta doesn't say anything about the actual lv.20 endgame in the final game.
But no, 'the gameplay is so shallow' and there is 'no incentive to explore' and 'there's so little content' and 'there's nothing to do', etc.
Whatever...