The issue here is assuming most Dems are progressives. Many dems fear the far left progressives. The squad is getting dismantled. The dems had an opportunity to get a real go getter pro in there to make up for Kamala's lack of political knowledge. Instead, they went with a man many consider wacky and too progressive. Easy to pick apart. Jailed people for not wearing masks but let rioters go free. Tampons in boys rooms etc. Kamala was horrible in the 2020 primaries for a reason. She has been described as an economic zero, with no clue on the real issues besides abortion. She never has shown aptitude, and the right are just using her own interviews against her. She checks diversity boxes, but her head is empty. A strong moderate could have eased people's minds on that with a strong ticket. I agree Progressives are excited, but moderates see the problem. Moderates destroyed her in the 2020 primaries. Actually, everyone did. She isn't strong, besides DEI. A strong VP pick could have put this in the bag.
That being said, Trumps pick was bad too. He could have grabbed some DEI points and went the other way.