Why is a 15 stage binary counter/divider so cumbersome?
The reason is that that's not all a counter needs to do.

Since any timer or counter will need to provide BCD counters for the seconds (and minutes and hours, if appropriate), along with display formatting and driving, it makes far more sense for the custom IC to incorporate both the oscillator and the divider chain into the IC, rather than having this as a second, external IC.  

What you seem to be asking is why nobody makes a 6-pin IC which takes power, ground, 2 pins for the crystal, and outputs a 1 Hz signal. Well, that's because there isn't much demand for it.

If you want 1 Hz, a much smaller solution is this ASTMK part, which provides 1 Hz logic-level output in a 2 mm x 1 mm package, which is smaller than a standard 32,768 crystal, which typically will run about 4 mm x 8 mm.