Why would I Want To Unlock My Data Card or Dongle?

You can save money when out of the country, and can also use the cheaper services from other providers, see the examples below.

Example 1: You are going from Lagos to Northern or Nigeria to Spain on holiday or business and will need use of the internet while out of the country, unlocking your data card and using a Sim from a service provider that supports internet access will save you money from roaming charges

Example 2: you have free internet access on your mobile phone Sim card as part of a contract and never really use it, no problem, pop the Sim into your unlocked data card and use your free bandwidth. just visit: http://www.enochcashzone..com

Yes,I agree with your points.
Nowadays we can use other network service on unlocked modem while move into other country and save money.
So only i unlocked my modem with a help of MobileUnlockSolutions.com I never had any problem.