Of course you _can_ but whatsapp is actively trying to prevent you from building those bots, and they may succeed well enough in their goal to have a measurable impact.

It is easy for us to say that a growth of whatsapp spam is inevitable but I would bet a key part of whatsapp strategy is to take that down to as close to nothing as possible. In comparison on fb and instagram spam is embraced. I think that is part of the reason why we see whatsapp taking a different direction than other seemingly similar social networking companies.