Is it is good to elect president for life?

No, electing someone to a position for life has some serious drawbacks, and unless the system they work inside of is designed to counteract these drawbacks, then it definitely can be a very bad thing.

The primary problem is lack of accountability. A "president for life" has no real incentive to change their behavior, since they have no possibility of losing the position, except through violent overthrow or resignation. In such a position, the president (by human nature) will tend to accumulate wealth and power, with no (or little) regard for their constituents.

Overall, even in the best system, electing someone "president for life" turns out about as well as having a monarch. Which, historically speaking, is pretty bad for everyone except the monarch.