Andy,
I agree with the safeguards put in place.
Although there are plenty of reasons Players choose to close Corporations...
1) You don't have enough workers to staff all your corporations. This has been very common recently, due to declining birth rates, and increasing Corporation sizes.
2) You want to make workers available to open a new Mining Corporation.
3) You are making room for a CEO controlled Corporation.
4) You are moving workers to new government jobs in Healthcare, the Military, or Education.
5) You are moving workers to a different country in your empire.
6) Your economy is overly reliant on a single product, or product type.
7) The products it consumes are in short supply. Causing it to cease production.
8) The product it produces has unstable demand.
9) The product it produces is suffering a severe long term oversupply.
Signed President of DanNation on LU