Not a big self defense pundit but here are my thoughts. Firearm makers make models that sell, the business, like every business is market driven, and other than the 100th. Anniversary 1911 nostalgia boom, where every maker offer a tribute pistol, the market is moving towards "tacticool". I have two objections.
Firstly, the light rail under the barrel adds bulk and weight to the front end of the pistol, which then requires a larger holster and may impede ability to un-holster in a time of necessity. All this without any "junk" hanging from the rail.
Secondly, even a small light up font is going to really affect the balance of the pistol. 1911's etc. are excellent, instinctively pointing pistols, UNTIL you hang a big dead mackerel to the front end of the barrel. OK, it's a light, not a dead stinking fish. But how often do you really need a light on the end of your pistol? Unless you are in Special Forces, SWAT, FBI HRT or SAS, I think a set of tritium sights or a trigger activated laser makes more sense. I also shoot a SIG Sauer P6 and prefer it to the newer SIG's with the rail.
For home security my choice is a shotgun, again without a light, if I need a light, I'll use a light, held away from my body on my offside. I sure as heck don't want to advertise my position with a big old "come and shoot me!" Or I'll just turn on the house lights before I go downstairs and watch the baddies scurry like cockroaches.
At least one maker already offers a pistol kit with two "lowers" and two barrels, one a shorter "carry" barrel the other a longer barrel with a barrel weight and compensator "forward" for target shooting. It's legal for that model since there is a separate "fire control group" that BATF has deemed the receiver for that model that can be transferred from one frame to the other. Such a solution, unfortunately, is impossible to implement in more conventional designs.
At some point I'm sure a custom house will open to retrofit these tacticool designs once the tacticool fever is broken and the embarrassment begins. For a couple of hundred bucks the rail will be ground off, and the lower repolished and refinished.