At least with Chrome you have a rough idea of who will be using your data - Google. I use Gmail at work, and I have an Android phone, so I'd be fooling myself if I were to say that Google weren't tracking me already.
With Firefox, it's a breach of trust. The analytics stuff was a major fuck-up, and I would've accepted that apology if they didn't then align themselves with a TV company to run a promotion in my browser.
I could understand all of it if the code base was amazing, but when your flagship product receives exploits from bugs raised over a decade ago, before Chrome even existed, it's hard to trust Mozilla to be able to compete with Google.
I don't get it. Criticizing Mozilla for those things is fair, but switching to Chrome as a reaction to them doesn't make sense to me.