Why Not Statehood For DC?

The DC voting rights bill died again earlier this week. Bernstein asks:

I still don't understand why the Democrats didn't just push through DC statehood while they had the chance, during the brief period in which they had 60 votes in the Senate.

Yes, there are a host of practical problems. The tax base is pretty slim: federal offices and non-profits, which DC has an abundance of, aren't going to bring in enough (or any) revenue. Here's a decent, if somewhat old, summary of the economic problems DC would face as a full fledged state. Joyner's solution:

As I’ve noted several times in the past, my personal preference would be retrocession, whether real or virtual. Essentially, giving DC minus the Bernstein carveout back to Maryland. That solves the problem of giving the District’s residents representation in Congress which I absolutely believe they deserve and yet not giving them the ridiculously outsized power that would come from statehood.

Just why, pray, is giving the 600,000 people who live in DC proper representation in the Congress granting us a "ridiculously outsized power." You mean: unlike North Dakota (pop. 650,000) or Alaska (pop. 700,000)? There is simply no way to justify spending trillions to bring "democracy" to Baghdad, while refusing to grant it to America's capital city. In fact, the US - because of this anachronism - is the only advanced democracy to bar the citizens of its own capital from having the franchise. I think this simple fact outweighs any practical argument whatever.