I'm saying the candidate that gets the most votes during the primaries doesn't necessarily translate to the best candidate for the general election. For either party.
We should pick the person with the most "motivated base"?
No, that's about as subjective a decision one can have. I wouldn't even begin to guess who has the most motivated base or how to determine it. I will say I think Biden is the most uninspiring choice the Democrats had and I suspect I am not alone or even in the minority in that sentiment. He also got the most delegates. Those two statements don't have to be mutually exclusive.
If these guys have such a motivated base, why didn't more of their base voting for them?
Preconceived opinions by pundits in the media is a big thumb on the scales for starters. The inequality of campaign resources between candidates would be another consideration. I'd also reiterate what's favourable in a primary doesn't always translate to favourable in a general election.
Regardless, if we disregard votes, how do we determine who has the most "motivated base"?
The votes should not be disregarded. Let's be very clear; I live in a country where we have only once in history had a say in who our Head of State should be and not a single Prime Minister in over the last decade running for election was ever voted in prior to reelection. A democratic process where the average person has at least some measure of control is very appealing to me. I'm not even saying that the system needs to be revised so candidates like Biden are less likely to win; that's replacing dog shit with cow shit and calling it progress.
What I am saying is that I think it's a mistake to make Biden the Democratic candidate for this election. I think the main reason is his lack of appeal. I also think the Democratic leadership don't feel that's a problem and aren't even making an effort to address it. So basically the campaign will be an exact replica of Clinton's 2016 and Kerry's 2004 campaigns that can be summarized as "I'm not the other guy - that's all I've got". I'm aware that I'm an outsider looking in on all this, but all I can give is my opinion and why I came to that opinion. I don't have a solution to it, I can't even say this needs to be fixed. If the Democratic party wants to snatch defeat from the jaws of victory that's their choice. I hope I'm wrong; I suspect I'm not.