First off while I see the logic of your 3 points I would like to set the idea of only punching paper and recreation aside for a moment. Think about it if we all truly bought handguns for being accurate paper punchers we would probably all own .22 target pistols, adn on the flip side if we were all just out for fun to get the adreneline pumping with big booms we would probably all own large calibre revolvers and DE's. So why then are the most common handguns that CGNers own(just a educated guess from what I read), mostly medium calibre combat pistols and practical mid sized revolvers? Sure, I like most people enjoy both being accurate as well as just having fun with firearms, however, I think, like most CGNers I think that it is valuable to have the skills to, if required and legal, use a firearm(handgun specifically) in a more practical defensive situation.
Now on to why I believe the 1911 is one of the best possible choices out there in terms of handguns. I will narrow this down to automatics as revolvers are really a seperate thing. To do this I will address the three points you brought up in order to point out that what you see as disadvantages(whether or not they affect us) are not bad.
First, the size and weight factor. In terms of concealability I feel 1911s are not at a disadvantage as they are fairly thin and with shorter frames(IE commander) are pretty compact in terms of demensions. While the weight is significant, a good solid belt will be able to hide the weight of a 1911 well. In terms of the ability to carry that weight, 37-40 ounces is not all that much for most people to carry.
Second, the magazine capacity which is limited due to the single stacked design. This is a trade off but not a bad one. In fact for concealed carry in the States, single stacked pistols are becoming more and more popular because most people realize 17 rounds is probably more than you will ever use in a self defense situation. Lets actually look at the capacity of a double stacked 45 to be fair(I will not get into the calibre debate), 13 rounds in a glock 21, so just one spare mag will make that up if you need to. Really unless you are going into an actual gunfight, 8 rounds of 45ACP will do everything you need in terms of defending yourself(but I still support the freedom to have 100 round drums if you want to). Plus you can buy 10 round 1911 mags if you really want.
Finally reliability, while I would agree that a new factory glock will be more reliable than a new factory 1911, 1911s are capable of being just as reliable as glocks. A broken in, well maintained, quality 1911, is right up top with glocks and other modern designs in terms of reliability, just don't expect an out of the box norinco wiht no lube to run perfect.
For numerous other reasons as other have mentioned 1911s are still one of the most popular pistols among civilians for a reason. Unless you are going to war or raiding mexican drug cartels, a 1911 do just fine, and if you are going to war or fighting cartels, just remember, in those situations where a glock might be more advantageous than a 1911, the purpose of your pistol is to fight your way back to your rifle(or more ammo).