This seems to be what everyone forgets when airing their grievances towards Apple's "Pro" line.
It's unfortunate but the number of people that may dislike this because of a lack of upgradability, etc is probably smaller than the number of people that just want a cool looking "pro" computer and have money to burn.
If you feel offended by those comment, that's on you, no one is actually judging you.
So, modularity is useful just not not as important as people assume. Computers are also not getting faster as quickly so using the same computer for ~4 years is now completely reasonable. Spread out of that period these start at ~80$ a month. You might drop that price some, but not as much as you probably assume without sacrificing.
They might not be optimal, but it's a reasonable option.
Now it might be a true statement that "if you're a professional video editor working with lots of files and 4k video, the Mac Pro doesn't meet your needs" or "if you're a professional data scientist working on cutting-edge machine learning with CUDA, the Mac Pro doesn't meet your needs".
But "professional" is a broad term. Very broad. It's hard to imagine a broader term. Even if we restricted that to "IT professional" or "professional programmer", it's still a very broad range of needs within that statement. And the Mac Pro lacks a very specific set of things that "professionals" may need, depending on their profession.
I'm willing to bet the number of professionals who need a Unix machine with a nice GUI that's well-supported by major software vendors and also well-supported by the manufacturer with retail stores (including tech support) in every city of any size far outweighs the number of professionals who need anything specific the Macbook Pro or Mac Pro are missing. Why, then, are they not considered "professionals"? And what other machine meets those very broadly applicable requirements?
Or how about this one? I need a Unix machine with a serial port and an Ethernet port for my job, and I also need the machine to be lightweight because I travel constantly, it needs to be able to be held with one hand as I'm standing in a datacenter, and I need long battery life because I can't carry a ton of cables through the datacenter as I'm moving around. What meets my needs as a professional? Sure, my needs are very specific... so are the needs of this hypothetical gold standard "professional" who needs what the Mac Pro doesn't have. I certainly don't need a powerful video card. Guess I'm not a professional, then?
It's the constant gatekeeping of "Mac(book) Pro computers aren't made for professionals because I made up my own definition of professional and you're not in it" that really grinds me the wrong way. I don't need to upgrade my RAM because by the time I need more, my work will just buy me a new one. Guess that means I'm not a professional?
I think a diagram better explains what I'm trying to say.
What I feel like Apple's target audience was in the past with their 'Pro' lines:
What I feel like Apple's target audience is now with their 'Pro' lines:
It still meets the requirements of a lot of professionals, and a lot of professionals are still going to use them. I'm not trying to say 'whether or not you are a professional is directly related to whether or not you use a macbook pro'. It is just that apple seems to be slowly targeting their "pro" lines more towards the consumer who like pro stuff side to capture more of that market than they are trying to move toward the professional side to capture more of that market. Instead of getting more ports and longer battery life at the sacrifice of weight, we get things like the touchbar and ever thinner machines that have trouble living upto the battery expectations. For a bunch of professionals that doesn't matter, it isn't what makes a macbook pro fit their requirements. But there seems to be a very vocal segment of professionals who sit on that left most edge concerned that what apple calls 'pro' is moving further away from meeting their requirements than closer.
Edit: it might be more clear to say the green circle is people who find a macbook pro to meet their requirements.
Maybe clueless people will buy this as a consumer machine, but it's designed and marketed as a workstation.