You do it because you want to advance your career.
And it not as uncommon as you think.
Start with Bcomm then CA
After CA apply to an Ibank or investment firm and study for the CFA
(Although its not that useful people do it cus everyone else has it)
Later on when you are mid 30 or so you might do the MBA for networking.
Also since both CA, CFA and MBA can be taken while you are working, all you are sacrificing is your time and energy.