Consider Shakespeare.
If you just consider him "great", and read him to appreciate him, then that is an ideological perspective.
You could say the way he treats xyz is a product of his times, that is a perspective.
If you say, he is over-rated and people have held him up to a high standard, that is also a particular ideological perspective.
Having a particular ideological perspective, and arguing against others does foster critical thinking, as long as you are arguing against another ideological perspective.
So if someone says, hey side X was the righteous side in this particular war, and someone else says no it was side Y, and a third person says they were all dirty, that's probably a good thing. It doesn't mean you can find a non-technical discipline free of ideology.