Don't get me wrong, this design isn't perfect. There is certainly room for improvement, like everything else on this planet. Actually, it has a lot of room for improvement. But is it really 'hideous', 'disappointing' or 'a step backwards'? Imo, people are critizing it way too quickly.
The colours
I have no idea why there's so much critism on this because people have been asking for more colourful macs for ages. Maybe the pastel colours aren't your thing, but they're supposed to be 'light and optimistic, while instantly brightening up any space'. And in my opinion, that's exactly what it does. Still don't like it? You always have silver.
But, maybe you're a more 'everything matte black' person. Then you're either a professional, a very boring person, or both. Like, Apple is trying to be optimistic and fit every colour of the rainbow in their lineup. So why tf would they offer space gray? If you want it to look cool, wait for the 27".
The chin
Of course, if I could choose, I want it to be gone too. But I understand why it's there and I can live with it. Here's why:
1. You concentrate on the screen anyways. Just like a hole punch or notch, the chin fades away after a while. And it doesn't even interrupt the screen itself, only making the front bigger.
2. It contains the six drivers and two pairs of woofers. If it gives me better sound experience, I'll happily accept a chin
3. Its value can't be too good. Remember that the price is 'only' 1299 dollars, you can only do so much with it. If it didn't have a chin, it'll probably come with a price hike. Guess what regular, non-techie customers rather want.
4. If the design is 'too' good, you might get a 'iPad Pro 2018/Apple Watch 4' situation; peaking too early. Apple is still struggling to add big updates with these two products.