I think it's just because of the way they designed it. You have some suites on the east side that are in between the first and second deck but on the west side, the suites between the first and second decks are (I believe) the Founders suites I think and they get their own personal lobby/common area outside of their suites. Idk, I could be wrong, but when if you watch the official renovation video, it gives you all the details on the renovated west side. So I guess they didn't want the peons to cross through the founders' suite area and then enter the west first deck from the top of the first level (like it is designed on the east side) which is why they put separate first deck entires in the middle of the deck instead of having people enter from the top of the first deck.