Sure, it's not as fast, but I can run and use Photoshop, Pixelmator, Acorn, GarageBand, Logic, Xcode, Final Cut, and many other apps just fine, along with League of Legends and most other games that the GPU can handle (though it can't handle many and often warns about heating up), while multitasking and plugged into a secondary 1920x1080 screen. It's actually amazing for an entire PC that doesn't even have any fans (as in active cooling.)
I honestly can't see how anyone fails to understand that this is an ultraportable whose use-case is clearly people that travel a lot and prefer to carry around as little as possible.
If you need a beefy CPU/GPU this is not for you. If you need a gajillion ports this is not for you. Why insist on getting something that isn't for you and then complaining about it?
However, while Safari always runs a lot better even with a lot more tabs, Firefox on my 1st-gen MacBook definitely doesn't take a whole 5 seconds to start. Could there be some resident third-party crap running in the background on yours?
The MacBook Air is "superior" in two objective specs: speed & price. That's honestly it, and it's not even that much faster. It also has more ports & a more traditional keyboard/trackpad, but those are subjective differences.
The two people I know with them can barely tell the difference between the Air keyboard and their MacBook keyboard, didn't realize the Force Touch trackpad wasn't a physical click, and only ever plug their computer into a charger or a projector which required an adapter on the Air anyways.
The MacBook blows the Air out of the water in every other way. Design, weight, thickness it's not even a contest. The screen is orders of magnitude better. Battery life is better, sleep/wake response is better, power draw is lower, charging is faster.
The plus for the MacBook is that it doesn't occur all that often.