You are right, any place can offer MBA, its almost like pisang goreng nowadays.
Hence only those really stand out will attract employers attention like FT100.
Rationale is because good MBAs have very stringent requirement.
Common requirement for good MBA normally will be:
1) GMAT marks (normally >600)
2) Minimum number of working experience in large MNCs or consulting company
3) Good underlying degree

If the university doesn't prescribe such requirement, you should know the quality of their students right?
Take for example, INSEAD MBA holder from Singapore normally earn $10,000 and above. That is roughly RM25,000 per month and RM 300,000 per annum. You will hardly find any employer paying that amount unless you are a senior manager with a very established Fortune500 companies.

MBA does not give you automatic passport (common misconception). It just complements or validate your existing ability. Most go for MBA to get the alumni network. For example, Stanford, Harvard and Wharton shares a common portal where the biggest companies headhunters will go. They have exclusive right on that, that's why you don't see companies like Microsoft, Google, Oracle put jobs ads.

Most people take MBA to work overseas. Best is MBA from US. UK normally very hard to get PR there due to lack of demand but they have good scholarship programs.