It is all in the "what do I get in return right now?" concept. Reduce pollution is a promise to give back a safer Earth, save climate, make life less painful in future etc. which are all far away and the current generation in power will probably retire long before anything significant extinction level occurs.

AI on the other hand promises immeidate gain(lot of expensive job automation = cost cutting) as well as future return on investment. Like someone said, IT has returns realized quickly in few years, so that is more lucrative than /reducing pollution/.

Also, reducing pollution requires money spent(cost) and everyone is afraid of the cost if it does not promise at least x2-5 minimum return gain immediately(or in few years).