Just a devil's advocate sort of position regarding the alcohol being included - I don't find the inclusion of one alcoholic beverage any different than including dessert. Overconsumption of either is bad for your health (I am not touching the subject of alcoholism here as it is a real and serious disease) and many people choose not to order either or not order alcohol or not order dessert. The dining plan is generally not a good value for those people.
My family usually enjoys alcohol but we do not always order dessert. For those making the "subsidy" argument, you could make the same argument about Disney "forcing" you to subsidize someone else's dessert.
The dining plan is not required - you just have to do the math to see if it's a good deal for your family. If you aren't a family who would order an expensive specialty beverage (whether alcohol or not), the dining plan may not make sense. Just as it might not make sense if you are someone who doesn't eat meat, doesn't eat dessert, a lighter eater, etc.
But all that said, I truly don't think the dining plan is aimed at those of us debating its merits on a fan message board - we know enough and plan enough to use the dining plan wisely or just not purchase it. The dining plan is aimed at the masses who call and book everything and want it "all inclusive" - disney is likely making a fortune off of those who buy the dining plan and leave credits unused. How many times have you seen a server or a quick service cashier explaining the dining entitlements? Those people (likely) paid a lot for the dining plan and don't even know what they got in exchange.
Bear in mind how little Disney pays for the cost of drinks versus the price they charge to guests. Having alcohol included will probably sell more dining plans to families in the top 20% of earners (and foreign visitors) and if that means losing sales to the more cost-conscious families, well, hey - that just seems to be the business model these days doesn't it?
And if the new alcohol inclusion doesn't sell more plans I'm sure that inclusion will be gone for 2019.