Okay I disagree with a lot of what you said in that. First stacks of doom if anything take less time then civ 5 combat. What "showdown" are you referring to? All stacks of doom did strategically was measuring a civ on their science, and or production. One would have no chance if you were a builder trying to survive a attack by an ai empire that spent the turns you were making wonders to make units. In civ 5 quality can actually beat quantity. How is being allowed to put a billion + men in one tile = 2 miles more realistic than only being allowed to only put 1000 men in one tile? Slower production times is to make it so that one cant achieve this so called blanket of doom as quickly. Lastly I'm almost positive that over 4 fifths of the people that have played civ 5 have never experienced one, the one fifth that had would have wanted to try. I don't understand the whole "omg I hate civ 5 because of the blanket of doom" thing, when almost no one has seen one (if you have seen one please say so in your post). But you believe what you believe and I believe what I believe and that's fine.
Okay, first off I edited your post a bit to improve readability.
Stacks of doom do tend to take less time, but I was referring to the times when huge stacks of doom went up against eachother, which do tend to take quite a bit of time especially if you don't have quick combat enabled, as I don't.
I disagree with you on your point that stacks of doom don't take tactical or strategical skill and wars are entirely decided by the production and science of the civs involved; although yes, that's a big part of it, there's still a lot of decisions you have to make. For example: I've got 3 cities in the far north, and I'm at war with the Ethiopians in the Southeast, and my stack of doom is currently advancing on them. Suddenly, the Chinese declare war and them and their vassals march their troops into my northern cities. Do I break off my invasion, possibly leaving my previous conquests and even my core cities undefended but hopefully making it in time to reinforce my northern territories, or do I press on with the invasion and hope I can scramble a decent defense force quickly enough to stop them?
This was a decision I actually had to make, and I chose to continue the invasion. I lost my cities, but took a few more from the Ethiopians. Who knows what would have happened if I had took the other route, but things certainly would have played out far differently. I consider a decision like this pretty equal to the tactical decisions you have to make in Civ 5, although something of this magnitude isn't exactly common, but neither is it a common thing in Civ 5 either.
And it's true that a Civ focusing on Wonders would be at a disadvantage compared to a Civ focusing on their military, but isn't that true also in Civ 5? Wouldn't the Civ in Civ 5 that builds 3 wonders instead of 10 units also generally lose? If the Civ in Civ 4 can muster a defense quick enough than it certainly has a fighting chance, and tactics are especially necessary when you don't have a big stack and you're playing defensively.
And yeah, with extremely large stacks it sometimes gets a bit ridiculous, but that happens pretty rarely. However, armies were historically thousands and tens of thousands of men strong, and 1upt just doesn't really reflect that.
You're right about slower production in that it is intended to alleviate the blanket of doom, but it happens anyway and I heavily dislike the slower production as mentioned here:
I also find that one of the biggest problems with Civ 5 is the slower production times, for me it just feels a lot more like a real empire when stuff is constantly going on
And I pretty clearly said that I have not experienced a blanket of doom, and that it only happens at high levels but it is still a pretty obvious problem with the game, though it doesn't affect me.