1. inflation rate, which is usually in double digits in Nepal

2. interest rate will not stay high as now

3. viability of the banks, therefore, the safety of your money should there be any disaster - big or small - in Nepal

4. As sidster mentioned, your personal safety as a high bank balance holder

But, these are all just minor inhibitors if you truly wish to return home, hence, can be dealt with appropriately.

Good luck.