For _them_ easy phone number porting, customer service reps being able to "fix" a paying customers message problems, and making it as easy as possible to have their customers send and receive more SMS messages are all directly bottom-line positive things.

Making any of that _harder_ for their customers will only reduce their profits and increase their support costs - at zero benefit to the Telco.

Your bank or ISP or email provider's security is not the Telco's problem - and they can't be expected to invest effort into it on behalf of non-paying 3rd parties...

This is what my local Telco Alliance told the banking industry here in .au back int 2012 (and 've kept it bookmarked ever since for all these discussions...):

"Stanton told iTnews that the telcos have decided not to extend the security mechanism protecting the mobile number portability database for reasons of competition and database performance.

Apart from making the porting process more time-consuming and less convenient for hundreds of thousands of Australians every year, additional ‘security’ may be seen as a tool to lock in customers, hinder number portability and thus be deemed to be anti-competitive," he said"

http://www.itnews.com.au/news/telcos-declare-sms-unsafe-for-...