For me, the issue has a couple of layers:
First, there's little I can do about it, even if I'm not on gmail. So many people are, so Google has copies of most of my email even if I'm not using them.
Second, this is a small wrong in the world; I've literally never heard of political violence linked to someone's use of Gmail, while I have heard this about a variety of other services. It's a little disturbing, but there are "evil corp" things much closer to home that I reserve my change-the-world energy for.
Third, on a basic level, there's nothing wrong with this service, or any of the various privacy-invading services. The problem is that, right now, the mega-corps are all so unrestricted from passing my data around to one another, building giant profiles.
What I want is to be able to share my data freely with anyone, but for them to be heavily restricted from sharing it, under serious penalty, until I say it's okay. I want a cultural and legal shift around privacy to take place, so that companies have to respect my ownership of my data as a primacy, but then I want them to be able to do whatever cool stuff they want with it.
Location sharing? That shit's awesome. If you're meeting up with people in a new city, there's no better way to do it. But my telco and mapping providers had better be under corporate death penalty not to share that with anyone, under any circumstances.
That's the world I want, not one where these things don't exist, just one where I and every other user of the tools is in charge of what we do with them.