I like what zen wrote as I usually do. A good response.
OP...its all about fit including how aggressive your fit is...saddle setback and bar position relative to your level of conditioning. A weak rider should ride more upright to take more pressure off the hands...which goes up the arms, into the shoulders/traps and neck. This is the whole premise of cruiser bikes.
The tradeoff is speed. You can't propel a bike as fast in the cruiser position because of air drag and muscle recruitment. The stronger the cyclist the greater the pedal force which neutralizes a more aggressive fit with less weight on the hands. Reduce those pedal forces = more weight on the hands.
Most average cyclists are better served with a bit more saddle setback aka behind KOPS and a higher handlebar. If you can't achieve this with a conventional frame and you think you may prefer a higher handlebar as many do, look into a comfort geometry road bike.