Mauricio, I fully concur. I am a great advocate of Whatsapp and/or Viber for messaging period. That includes images. I wouldn't even raise the issue, but as the recipient I'd expect it to work. And that's where my complaint arises.
And it's not a age mind set either, my mother-in-law would be lost without her Whatsapp and Skype and she turned 80 last week!!! Her Android phone and iPads are the first computers she's ever worked on.