Is Warmer Weather Necessarily Worse?

What has always troubled me the most with the view that we needs to stop "climate change" in the form of "global warming" is the idea that it would be bad if the Earth became warmer.

Sure, that could be negative in some areas for some reasons, but it would also be beneficial in other areas for other reasons. Suppose for example that Antarctica, or at least parts of it, would become habitable due to a warmer climate, wouldn't that be a good thing that could possibly outweigh possible problems elsewhere?

So what is there to say that the pre-industrial  era climate is really the optimal climate? That the benefits of a possible warmer climates wouldn't outweigh the disadvantages? I have asked that many times to Al Gore supporters and either gotten no answer at all, or some list of alleged (and exaggerated) disadvantages that completely overlooked the benefits.

If one needs an example of why cold weather is bad, the current problems in the European traffic system is a good example.

Note that some "climate change" theories argue that "global warming" could lead to colder weather in for example northern Europe. But even assuming that this is really true, it begs the question of why colder weather is bad there but good everywhere else. And this cold weather will largelly undo the initial warming effect, leaving us with little to worry about, assuming "global warming" is bad.