Considering the lifetime of a process, assuming that its short lived and its not ok to accept memory leaks in the code.
1. Same thing might happen to a daemon - which will bring down system
2. Trigger OOM errror
3. A bug in short lived process (assuming its short lived) which eventually might be using up all the resources.
4. Even for a short lived process, if the memory consumption is exponential, then we are done in much lesser time
So, the rule is - no memory leaks in the code and no memory leaks whatever be the life span of the process memory image