The last that I’ve seen, UA is no longer offering BE on walk-up style fares except under the specific circumstance that Kacee saw — when it’s only one way of a round-trip and BE is available (on a non-walk-up fare) in the other direction. The only exception are a few legitimately low-price fares that have been popping up, where UA will file a 0-advance-purchase deep discount fare that’s not paired with a regular economy fare. If you want regular economy, you have to pay walk-up prices, but BE is significantly cheaper (examples have been in the hundreds of dollars).

If DL is truly doing what you’re saying — which, if you were to read the gleeful posts by certain members of this forum, is completely impossible because DL is nearly perfect and knows that BE is a horribly offensive product to business travelers — that’s new for them, and a worrying sign that UA’s original plan was correct and may return. (UA originally expected the other airlines to follow suit and only rolled back the broader BE implementation because they didn’t).

I agree that the rules are more Draconian on UA. I almost give them credit for the check-in thing, though, because they’re really trying to keep people from bringing a full-size carry on to the gate and then getting upset. I say “almost” because it’s sort of like praising them for not shooting their entire foot off — “good job, guys the ankle’s still intact!” — but more passengers screaming at the gate agent wouldn’t be good for anyone.