IOT (and IIOT) is very different from SCADA. Although IOT and SCADA may overlap, the two are not interchangeable, but complementary.
SCADA is primarily about control, especially for operational systems in real-time == things engineers care about.
IOT is primarily about business intelligence (BI), including long term data aggregation and analysis == things business managers care about.
A good example is for consumables. E.g., a package delivery company has 20,000 delivery trucks and spend millions in tire replacements (buying tires, stocking them at warehouses, distributing them to repair facilities, installing them, disposing them, etc.) They want to capture truck and tire parameters, aggregate the data over long periods of time, overlay supply chain (SCM), geographic (GIS) and even financial data to perform trend analytics, use machine learning to devise optimal improvements, etc.
SCADA would be ill suited for these types of tasks. Tires are consumables and trucks are mobile. At best SCADA may be leveraged as an expensive way to capture parameters. But what about the data aggregation? Business analytics? Decision support?
Consumer IOT won't cut it either... it's not just about operating conditions / temperature range, but about the industrial infrastructure and systems required to support IIOT. (E.g., "big data" / Hadoop, machine learning farms, BI/visualization tools, etc.)