Below the 100D? You mean the market segment that doesn't exist because it's IQ is indistinguishable from iPhones? Get a clue Canon.
You mean the iPhone produces the same image quality as the T3/1100D 12 MP APS-C sensor? Get a clue HurtinMinorKey.
In the hands of the people who would actually buy something on par with the T3, yes. Also, the iphone has vastly superior video.
I'm always surprised by how detached some people on here become from the "common" market, where entry level is king.
I started with the equivalent of the T3 (The Rebel XS/1000D). And yes, it was VERY entry level, but you know what? I learned alot from that camera, it STILL takes great pictures (with the right glass), and I'm sorry, but even the absolute cheapest SLR with the crappiest kit lens takes images FAR BEYOND what an iphone does. I still use my XS for time lapses and just a "throw it in the back seat" sort of camera.
Don't get me know, I LOVE the fact that pretty much everybody has a camera in their pocket now. From getting news as it actually happens, to civil liberties, to just plain fun it has been a wonderful revolution.
But to say that the "average" person with an iphone wouldn't get better IQ from an entry level DSLR is simply ludicrous.
As for video, wiki shows the T3 is capable of 720p video. While not 1080p, that's actually pretty good (alot of people shoot 720p anyways to get the 60fps framerate for flexibility in post to slow video down).
Is the fact that the T3 does "only" 720p while the iPhone does 1080p the reason you label the iPhone's video capabilities as "vastly superior"? If so, that's a load of rubbish. 1080p video off a cell phone is so massively compressed it's NOWHERE near as good as what you get from even an entry level DSLR. I've seen the 1080p video out of an iPhone. It's good, but it's blown away from the 720p and 1080p I get from my DSLRs (and even P&Ss). And that's in good light. Drop the light and any smartphone's video will be a mess of compression artefacts and digital noise from having such a small sensor.
Finally, as a reminder: not everybody has $3000+ for a DSLR. And I'm sorry, for the VAST majority of images even seasoned photographers take the T3 would "work" well enough. The quality of image you get from even an entry level APS-C camera these days is astonishing.