Because the sign indicating it IS Eglinton Avenue is located only on the far side of the intersection itself.
By the time you get close enough to realise this, and if you want to turn left, then (assuming of course you're in the right lane where logic, courtesy and the law require you to be) you've got three lanes plus (in this case) two left-turn lanes to negotiate, all in about a hundred meters of 60 km/h road.
Why isn't there a sign a few hundred metres back up the road, indicating that this up-coming intersection is in fact Eglinton? You'd have plenty of time to react.
Not everybody can afford a car with SatNav, with Doris of the Dashboard telling you where you are at every moment.
Sure, you'd still want the sign at the intersection itself.
But more advance warning?
It would make a huge difference.
I'm not picking on Mississauga here. Every municipality in the GTA - frankly, almost everywhere in the world - is guilty of this to some degree.
What makes it particularly frustrating is that not half a klick away, just around that left-hand turn, they have done exactly that. If you're headed west on Eglinton approaching Credit Valley Road, here's what you see:
Well, they could put a sign on a pole in the centre median too, as they do in some instances.
Here, they've even put the house number range on the sign, so if you know the exact address you're looking for, you know which way you have to turn.
It is clear then that somebody within the Mississauga transportation department (road sign division...) knows how this is supposed to be done.
My question: why aren't they consistently doing it correctly?
Of course, if they'd just eliminate these stupid, sprawling, horribly dangerous, traffic-light-controlled multi-lane intersections altogether and replace them with roundabouts, the problem (and dozens of others) would cease to exist.
But no municipality within the GTA is smart enough to figure that out; I admit, I'm aiming low here, hoping that a few more properly-positioned road signs can at least alleviate the danger.
It would be a start.