It's a progression. It's not a huge problem, by itself, for either. But Google shareholders want to continue the same YoY gains. The only cash cow is search, so they continue to take screen real estate that used to go to others, and take it for themselves. Whether that's more ads, or more widgets, or whatever.

Yes, it's legal. But it does reduce visitor interactions for those sites. Reduced visitor interactions isn't good for web sites...it takes away incentives, reduces brand value, reduces revenue. Eventually, that is not great for consumers.

Ever been a middleman? Squeeze your suppliers enough, and you kill them. The next supplier will pre-emptively cut quality, features, etc, because they know you're going to try and squeeze them to death.

"If I'm searching for a flight status online, it's because I'm picking someone up"

That's one use case, it's not all of them. There's middle ground too, like the bones they throw Wikipedia in the form of links for more info.