I can only tell you why I like and carry one, and many of these have been discussed already.
1. It is steel. It has heft (which does not mean it is heavy, I do not walk around with my pants around my knees because of the weight). The weight helps it control recoil to some extent. Also, in the unlikely event I do need to strike someone with the weapon, they will know that they have been struck.
2. Mine is reliable. It is as reliable as a brick. It has not failed me. Ever.
3. It shoots a big bullet that has been stopping bad guys reliably for around 100 years. I want a bullet, that if it does not expand because the hollow point gets plugged with material, will still whack a bad guy with some authority. When I need to shoot someone, I want a cartridge that will allow this bad guy to know that he has been shot.
4. It is slim enough to conceal easily, yet is still a large, full size combat-type handgun that I can carry openly on the farm and it will do the job at either place. This way, I just need one carry sidearm, not two.
5. The 1911 fits my hand and I shoot it well.
6. The trigger is good like no other handgun that I have ever shot on a regular basis.
7. It can be easily customized to the way I like it. For example, Novak sights and a straight mainspring housing with a lanyard loop. I am a throwback and like lanyards when working outside. Especially when around the water.
8. I have never accidentally discharged one that had the safety engaged.
All of this is not to say there are not equally good sidearms out there, many that cost less. But hey, a Yugo was cheap too, and I never wanted one. Yes, I know that other handguns work, (my Glock, XD, Beretta, etc. is better), my wife carries a Beretta 92 because it works for her.
I can some it all up with a little anecdote. A friend of mine asked to borrow a handgun so he could qualify for his concealed handgun license. In AR, if you qualify with a revolver, for some reason, the license is restricted so that you can only carry a revolver. He wanted an unrestricted license. After shooting it that day, he told me he did great with it and loved it. He really impressed the instructor and this guy is not a regular "shooter", per se.
However, after raving about it, he decided to buy a Glock. He thought since it was newer, it had to be better. He loved my gun, but went another way. Does that make him wrong? Of course not.
I am a fan of the 1911, does that make me wrong?