1. You want to open a trading account with a broker 2. You want to open a fixed account to get a credit card in Thai bank, and also a checking account 3. Your spouse can obtain a Non-O visa and stay with you. 4. It is easier to send money out of the country if you needed to do that. 5. You want to enrollment in the Thai Social Security system, which not only provides full health care coverage at a very low price but which you can remain in for life even after you stop working provided you keep up the small payments. 6. You want to have a Thai driving license 7. You want to send your kids to a Thai public school at low cost. 8. You want to apply for a visa to other countries which is often not possible for holders of some passports if they do not have a work permit. Filipinos. Indians, Iranians, Chinese etc. 9. Improved status of stay in the kingdom. Being a tourist or a student may not be possible forever but being employed with a work permit is.
You can add more if I missed any..
If you have the above needs and cannot get a work permit, contact me and I will give you the solution.