It amazes me how some people see life and nature. Life is not all rosy and therefore why should a nature programme convey the wrong messages.
If you can not watch a programme of this type, then do not watch it. I assume all TV's have an off button and these days there are so many channels, you can just turn over and watch something else.
Sometime ago people were complaining that the nature programmes were not portraying nature correctly and they objected. Now that it is, they are objecting.  It may be these people do not want nature programmes and if so, they should watch something else.
But we do live in a democratic country, or that is what it says on the tin, so people are entitled to express their opinions.