Engineers vs Biologists

Today, in my biochemistry lecture, we were studying about environmental issues such as protecting the trees, water hygiene, pollutions and stuff ....

And I was thinking, WE(engineers), build structures and facilities such as dams, housing areas, factories to benefit US(human), while THEY(biologists) protest against US(engineers) to protect those creatures called "animals" ! Its like a war between human and human for the sake of saving animals. How contradictorily is that ?

I wonder, do biologists and engineers get along? and what are WE(engineers) doing in a [biology] class?
coz whenever we build something, THEY(biologists) are always there:

"this will lead to forest destruction, ....habitat destroyed, ....climate change, ....endangered species, ....extinction ...blah blah blah.........."

Theres just something culturally different between biologists and engineers. We are birthed from the same fundamental origin, but came out as two different branches that protest against each other.
Yet, ironically, we engineers are studying biology.



And there goes my 1 hour lecture, thinking about these irrelevant stuff...