Another part of the picture is that some other PLC's require you to use timers in the "mid-branch" method, or are at least more commonly used that way.
In AB PLC's, most instructions other than your standard XIC/XIO and comparators are what you might describe as "straight through" instructions - i.e. if the rung-in condition is true, so is the rung-out condition. This is useful, because it allows you to put several instructions in series as we're describing. The timer is included in this - if you felt so inclined, you could put 20 timers all in series and they would all start and stop their timing operations together.
However, in a Siemens S7 PLC, timers don't operate like that. They don't pass the "rung power" straight through. A delay-on timer in Siemens land will only pass the "rung power" out the right-hand-side of the instruction once the preset time has elapsed. While these timers do have a .DN bit (actually a .Q bit, in Siemens-speak), and could in theory be used the same way as the AB timer in
George's post #3, it's often simpler to just put them in series, as with George's post immediately above this one. Even simpler, because unlike George's example above, you don't need to worry about the .DN bit after the timer - that operation is performed implicitly by the timer instruction itself.
So, all that waffle just goes to say - if someone is used to the Siemens way of doing timers, its quite plausible that when switching to an AB platform, they'd default to using timers mid-rung (with the necessary addition of the trailing XIC Timer.DN bit), since it's the most similar to their familiar programming workflow.
To me, this is an example of the double-edged power of AB PLC's - they tend to allow you to do things in a myriad of different ways, which is great because you have almost unlimited flexibility in how you approach and solve a problem. But it can be not so great, because if the wrong sort of programmer gets a hold of an AB PLC, they have almost unlimited flexibility in how they approach and solve a problem