Because I had a 58T chainring lying around, and am addicted to silly gearing. Also, it's not like I can't get the same range of gears, by having larger cogs, but then can also go down to silly ratios like 58x12, which I thought was a good idea for a while
Why 58t? surely something like a 48/14 will suffice, or even a 52/13 if you need it that high.