I disagree with your statement Dustydevil as I certainly see the advantages in a providing warnings through text messaging.
"What is wrong with taking a look at the sky around you?"
- This often requires an understanding of storm structure, something many in the general public do not have (nothing wrong with that at all - totally understandable). I think most people know a bad storm when they see one. Sometimes though it is easy to be tricked, for example, dark clouds or a visually impressive gust front on a weak squall line.
- Thick low-level cloud can often obscure storm structure making it difficult to judge severity or lack thereof, even for an experienced individual.
- Of course there is also the more simple reason that people may be just too busy doing other things, such as working, to pay attention to what the weather is doing.
SMS warnings are also a useful heads up for upcoming weather event. I should also disclose that I did work for the Early Warning Network for a short period of time so my opinions may be biased.