On the surface that sounds right. HOWEVER, it is based on a faulty assumption. "really was by blowing air on the sensor"
The Engine Temperature Sensor is buried deep in the metal of the cylinder head. The only way the fan blowing can reduce the temperature that the sensor reads is by cooling the cylinder head around the sensor. That is what you want to happen...actually cool the cylinder heads.
To be clear, the sensor is not reading temps that are outside the engine (where the fans are) it is reading the temperature inside the metal of the head, right near the combustion chamber.
That said, I have heard of a few people that have installed fans and oil coolers that have reported that they have not experienced any significant drop in engine or oil temps. I don't know why.
I have personally done extensive testing on a half dozen different bikes and trikes and always seen a very measurable drop in temps. (see video and chart below)
One thing is sure, if the factory temps are not brought down, there will be accelerated engine wear, just like you experienced.
Full report related to the above chart can be seen HERE.
Kevin