Not much data, but then not rich target audience
Mobile data, especially when it sets itself to roaming without leaving the shores, is so convenient but boy is it costly. Where it's possible to earn less a month than the cost of my sim-only phone package, it makes sense to have clear national consistency. 10MB may be irritatingly small for those of us who live online, but for an emerging market it makes a lot of sense.
I use ~15-20 GB of mobile data monthly across two providers, I shudder to think hire many nag texts I'd get, mind ;-)