Agile isn't an excuse not to meet deadlines, in fact the Agile Manifesto is all about providing quality early and then iterating. Agile is all about reducing scope to maintain quality and measuring the velocity that your teams can complete work so that you can provide accurate plans.
"Alpha" is not a term I would use to describe a quality product.
There is nothing in that manifesto about promising a load of features, expecting the customer to make do with an Alpha and telling them they "don't understand development" when they start to wonder if they will ever recieve a robust released product or any of the features they expected.
Yeah, one of the key points of Agile is that every iteration you have something that can be considered a working product. Not after day 1 of course, but, you know, after 8 years and 400 million you'd generally already would have had a stable working product for many years.