My primary complaint is that they have a bunch of ad placements on the product out of the box when it's opened for the first time and any time I set up a new system I have to go configure Firefox to not be annoying by default. It makes the Firefox experience feel subversive and untrustworthy because this freshly installed application is obviously bedfellows with advertisers. I know I can't trust advertisers with my data or browser behavior, so why should I trust Firefox with it? If I stop using Firefox for a little while, they _so helpfully_ offer to reset my configuration back to default so those ads will get shown again. It's a hostile experience.

Additionally, my perception (from posts and discussions like these, I'm not a financial analyst and I have no meaningful insights into their business) is also that they probably receive enough funding through non-advertising means that they don't actually need to do this if they were to pare back the nonsense spending they're so greatly known for.