Neither of those articles are worth their salt.
But here's why you were Negged:
1.)kamala Harris is far from an idiot

2.)Beto is the second most popular Democrat, 3rd if you shoe horn Sanders in
3.)The war cry of progressives was been to run on popular policy that Americans want to get behind - - both Beto and Harris are Doing that
Sit down child.
Admittedly my disagreements with Harris mostly come from her tweeting about how Americans deserve a roof over their heads and their lights on only if they hold a full-time job, and her hawkish comments regarding Syria, other than that she's fine from what I've seen I suppose.
Beto however is definitely not the progressive you seem to think he is. The article highlights him not participating in various progressive moves, never joining Congressional Progressive Caucus while in congress and instead being a part of the New Democratic Caucus, standing on the sidelines for the 2016 presidential election, and not sponsoring the free college house bill, or the single-payer healthcare bill.
He also once challenged the consensus on pro-Israel stances, quickly redacted after AIPAC donors showed him what's good, and approved all further aid to Israel. He didn't even go as far as to sponsor a bill that would prohibit aid to Israeli units that are proven to abuse children.
The article also highlights how his language about healthcare changed throughout his campaign until the present from a "single-payer healthcare system for all Americans" to "universal, guaranteed, high-quality health care for all" to then eventually him being open to a single-payer, dual system, or other systems that guarantee affordable healthcare for all, a clear difference.
With receipts too.
Would Beto be alright? Possibly. Is Beto some sort of progressive champion rather than a man simply using vaguely progressive rhetoric while really being more entrenched in the Hillary Clinton camp? No. Ideological purity isn't something that is realistic, but I don't see why Bernie should endorse him since he clearly doesn't really have the progressive credentials his rhetoric would have you believe.