Is horse racing any less cruel or sad?
Yes and it's a chalk and cheese comparison.
I'd happily see greyhound racing banned in Australia, but think horse racing is well-regulated and the animals, are on the whole, well-looked after.
There of course will be some bad eggs out there looking after the horses, but then there are arseholes out there looking after human athletes too (eg. systematic doping to various Olympic teams and the Essendon FC). It's a perennial fight, but not worth banning sport over.