First, one random decision made by the Indian telecom regulatory agencies that has really helped: mobile phone numbers are clearly distinguishable from land-line phone numbers. This makes SMS very predictable in India; you instantly know if the receiving number is ‘SMS-capable’ or not. In US, for example, there is no apriori way of knowing if a given phone number is mobile, so there is obvious hesitance in sending SMS’ that might or might not reach the recipient.
Second, SMS is very cheap in India. As is well-known, sending SMS literally costs the telecom operators nothing – the SMS data payload simply gets added to the ‘ping’ that every cellphone sends to the nearest cell tower periodically. For this reason, in India and other countries, thanks to cut-throat competition, the telcos either charge nothing, or very little, for SMS messages. In US, mostly because of implicit collusion, the telcos charge and arm and leg for this highly lucrative pure-profit center.
As a result, even if you know that the phone number you’re calling is mobile, and even if you opted for an SMS plan, you still can’t assume that the other party has an SMS plan. Of course, if you did send the SMS, it would definitely reach the other party; they’d just have to pay for that message on their end. Why bother?
(Of course, I’m talking about the normal citizenry here, most of these are non-issues for the illuminati and the glitterati)
So, an obtuse decision by a governmental agency, combined with private sector greed, has made US much less Text-capable than India.