Mount Kunlun is considered a sacred place in this world, and as everyone knows, anywhere branded as a sacred place, regardless of its true merit, certainly sets a high threshold for entry.
Without a fitting identity, it really isn't easy to get in.
This is similar to the prestigious Tsinghua and Peking universities in another world, where as a common tourist you can at most roam the periphery and take a tour, but to expect the university president to come out, keep company, and offer a toast is rather far-fetched.
So, to find the Queen Mother of the West, simply going to Mount Kunlun is obviously not enough. Why would she, busy dealing with a myriad of affairs, agree to see you?