Remember the GMAT isn't a test like any other you've taken before -- it's not testing concepts only. It's testing your readiness for the challenges of graduate business school. That's why it tests the following to a greater degree than other tests:
1. Your executive reasoning skills including things like unearthing hidden information and visualizing quant questions to expose more of the available information.
2. Time management -- making tradeoff decisions, knowing when to let go of a question, how to use tools like estimation to save time and selective skipping are all part of the ability to cope with high pressure situations far beyond the GMAT
3. Following consistent process across questions -- rather than randomly applying processes.
These are all thing the GMAT tests -- running out time for the final question or questions is a sign of basic challenges of coping with high pressure analytics situations.