I'm not saying that the muscles of the lower legs can't grow. Of course they can. Just not enough to make you happy if you aren't already endowed.
They won't grow much beyond their untrained state even under ideal conditions. Isolation movements for the calf don't provide nearly enough tension to elicit what little growth is possible. And besides, articulation of the ankle joint isn't what the triceps surae (the collective name for the three-headed muscle of the lower leg that includes the gastrocnemius and the soleus) are designed for.
Some muscles are just better designed to resist movement and stabilize loads while others are designed to provide movement through a large range of motion. The movement-resisting muscles include those of the extremities (ankle, toe, wrist, and finger muscles) and of the spine (trapezius, serrati, rectus abdominis, etc). The muscles that generate vigorous movement over a long range include all those of the shoulders, elbows, hips, and knees.
Calf, forearm, neck, and spine musculature are best helped when you force them to hold healthy position against load, not by moving a load over a distance. Presses, rows, pulls, and squats are valid; wrist curls and extensions, calf raises, neck machines, and trunk twisting, crunching, and extending not so much. Again, you really shouldn't be doing range of motion exercises for the wrists, ankles, and neck and spine. All the muscles controlling these areas are designed to resist movement, not create movement.
Instead, stabilizing heavy weights while standing and walking and pushing or pulling --such as with the squat and deadlift and a heavy sled/car push/pull-- and just plain getting heavier are the best way by far to get the calves to grow however much they can.
What do you think will look bigger and thicker: the forearms of a 130-lb trainee doing endless sets of wrist curls...or the forearms of that same trainee at 190 lbs who deadlifts 500 lbs for reps?
Back to the calves: can the 130-lb trainee do calve raises and get the same calves as he would have were he instead to work up to 190 lbs with an Olympic back squat of 400 lbs for reps?
I spent many years as a 130-pounder working my calves with some combination of high intensity, volume, and frequency. They got a bit more defined, but they never grew. When I ignored my calves entirely and just got bigger and stronger, I found myself in the 190-lb range with calves a couple of inches thicker. (My calves are still embarrassing at 15" around each, cold...but as embarrassing as my high cut, 15" calves are now, they are a lot less embarrassing than when I was 130 lbs and my calves were just over 12".)
These high-cut, skinny 15-inchers at 190 lbs
are still preferrable to 12-inchers at 130 lbs.
People generally recognize how hard the entire body has to work to keep the lifter-barbell system in balance as the hip and knee muscles actually create motion. People get that the traps are working to bear the weight, as are all the muscles all around the spine. But they forget that it takes mighty plantar flexors to stabilize the ankles as the lifter squats up and down. When a lifter squats down under load, the triceps surae work very hard to keep the lower legs from pitching forward too much at the bottom and letting the lifter-barbell complex crash to the ground.
Going from squatting 135 lbs to squatting 405 lbs is going to do far more for a lifter's calves than all the combinations of weights, sets, and reps of isolated planter flexion. Guys who get their Olympic back squats up to the 400 and 500 lb range know what a waste of time it is to do direct calf (and forearm) work.
And if you're still not convinced, remember this: professionally competitive bodybuilders with the best genetics for muscle gain and response to anabolic steroids STILL opt for calf implants if they aren't lucky enough to have long, thick calf muscles naturally. Do you think these guys aren't working their calves properly? That they are dedicated enough to put all those drugs in their systems and all those hours in the gym, but are just too lazy to work their preternaturally pathetic calves properly?
Under the best conditions of drugs, training, and otherwise good muscular potential, calves can be frustrating and remain relatively small. The best training for them is just to get bigger while forcing them to stabilize greater weights in the squat or leg press or heavy sled push. And even under the best circumstances, they may always lag behind the rest of your physique.
Look at the bright side, however: knowing this, you can stop feeling guilty about not doing all those stupid calf raises.
