The Pro tour guys do not all look so balanced, nor do many track sprinters - running and cycling. "Good" is reducing risk of injury and performing better at your sport.

If you believe all muscles and ligaments (I keep mentioning those) can be maximally developed at the same rate (obviously you get closer if everything is done slowly), then none of what I am saying makes sense. If you think areas of the body develop at different rates consider this example.

Example:
Say a normal "balanced" person with little lifting experience can do a squat with say 100# and everything balances, and they look great.
Now they want to bike race and use weights to get stronger and they have a 5 month off season to focus on building mass - where they want it.

Say that person can build the strength to squat 200# through diet and training (a lot being neuromuscular) before they can build the supporting muscles and ligaments to safely stabilize that weight in a cycling width stance...

Should they:
1 Do squats by using lighter weights developing everything in balance and get to that 200# more slowly - likely not in that off season.
2 Use other exercises for core and machines to stabilize weight and develop the primary muscles that would allow them to squat (other than injury risk) 200#+ more quickly. And by the time scenario #1 is at 200# they are at 250# and riding.

Clearly we are using method 2. I wouldn't be surprised if some supporting muscles and ligaments for good squats where not developed. But we have maximized those needed to go forward faster on a bicycle.