It's because they're obsessed with weight and economy (New Apple) as opposed to function and utility (Old Apple). I'm sure Jonny Ive could still make it look sleek, even if it was a tad thicker and heavier.
What do they not understand about what pro users care about?
The revisionism and misplaced nostalgia here is easily the most hilarious part of these forums.
The G4 cube?
Removing arrow keys from old Macs to force devs to code for windowed environments?
Bye-bye legacy connectors on the original iMac?
Apple has almost always been, for better or for worse, about enforcing their vision of things. This is good if you like it and it fits you and bad otherwise. It's not new though.
Styling has always been important to Apple and sometimes even at the cost of function. This isn't an Ive thing, it's a company thing and it has been for as long as I can remember. Go watch an old video of Jobs introducing the iMac—actually talking about how much better looking the machine is was noteworthy in their presentation. I mean, if by "old Apple" you're talking about the Woz days you might have a point, but Apple has always been like this.
The primary change isn't form over function but rather who their target audience is. A company that was once supported by creative professionals isn't now. It's a strange world where I see creatives buying Windows and developers buying Macs but that's where we are.
And I think I lot people who look at specs without using these machines as a whole don't realize that Apple does put a lot of thought into the practical use of these machines. While PC makes cram a ton of battery-inefficient RAM in their machines to satisfy that crowd, Apple has power efficiency (and seriously, more people care about that than the tiny number that honestly needs 32GB of RAM) and they focused on SSDs that are—for lack of a better phrase—just plain stupid fast. In real world use, what is going to have a greater impact on the greatest number of users?
Who is the crowd than needs 32GB of RAM for the most part? Seriously. Who are they? I realize they exist but is the number high enough to justify compromising their design? Even the people who WANT that functionality would have a hard time arguing that it makes sense from a design or a business perspective. (And if you want the mobile brick laptop... exactly when was Apple your option?)
I will say, from my whole two days of work with this new machine... I love it. The size is great. TouchID is so nice. The Touch Bar is... interesting? Neat? (I didn't use function keys basically every so, as much of a novelty as it is, it's seen more use than the function keys ever did.) Huge touchpad? Guess how many more people are going to benefit from that than 32GB of RAM. (I even like the keyboard given some time with it. I don't love it but I can't say I loved the prior MacBook Pro keyboard either.)