Q:

What is the problem with adjusting brake levers to end their travel "too close" to the handlebars?

I've recently increased my cycling (as a form of alternate transportation far more so than a sport).  I got a nicely rebuilt old Schwinn converted to take STI shifters.  Now that I've spent the time to get more comfortable riding a road bike, I would like to get used to riding in the drops for better efficiency on longer rides.  My problem is that I have pretty short fingers.
Even the cross-top levers I got installed to help me get back to riding in a more similar position to my MTB when I was a kid are a little bit of a stretch.  When I'm in the drops, I can barely reach the brake levers at all as they sit (adjusted to leave just about two fingers of space when squeezed to the end of their travel, as is "correct").  Which leads to my real question:
What exactly would be the problem/danger with tightening the adjuster on my brake levers to bring them a bit closer to the bars where I might be able to reach them better?

A:

The issue with having brake levers which have travel that ends very close to the bars is that, as the brake pads wear down, the brake levers will hit the handlebars before the brakes are fully engaged.
This can be mitigated by regularly inspecting your brake pads and adjusting the brakes to compensate for normal pad wear. You could have them that close if you stayed on top of the adjustment demands, but since the average rider does not adjust their brakes this frequently or pay as close attention to this, common advice is to avoid having the levers too close to the bar.

