Singling this part of the post out because it just seems so blatantly incorrect/biased. If I'm taking this out of context let me know, but I don't think I am.
actually hitting someone with a projectile offstage rarely ever happens outside of poor DI.
I don't know what game you're playing but it must not be Smash 4. Using projectiles to gimp or aid in gimping is a common and effective tool, especially if said projectiles are affected by gravity. In most cases the purpose of throwing out projectiles at an offstage opponent isn't to flat-out gimp but to interrupt recoveries, rack up damage and put them in unfavorable positions. If it ends up doing the job, great! But typically they won't. Projectiles are especially effective against characters with poor recoveries like Ganon, since they're unable to significantly alter the angles they recover from.
Let's take Villager as an example. He's a bit extreme, since he has a lot of different projectiles, but I'm mainly going to focus on Lloid Rocket and his dash attack. Lloid Rocket flies straight and is good at snuffing direct attempts at recovering. His dash attack, on the other hand, flies downward, pulled by gravity. Together they can cover most angles opponents from below the stage will try to recover from. Dash attack is limited it its execution but similar in how it flies to ROB's Gyro. (His FSmash is a special case and is really dumb if it hits characters like Ganon with it because it hits so hard).
Dedede and his Gordos are another example of a gravity-drawn projectile. They're pretty nice because you can alter how they fly to a decent degree. Now, Dedede's already good at gimping but his Gordos just give him aime added control. They're massive, deal good damage, and since they hang around, can give Dedede ample time to capitalize on their presence. Any recovery without and active hitbox can he severely interrupted by them, and even some with active hitboxes may be in jeopardy since Gordos can trade with attacks.
Now, back to ROB and his projectiles. Robo Beam is kind of bad for this since it usually lacks knockback but can be used to snipe second jumps. I personally love using the gyro to hit people offstage since it can fly varying distances depending on its charge (to say nothing of when ROB's holding it). I've become pretty good at hitting people at a distance with the gyro, and it can create some nasty situations where the opponent can either choose to be hit by it or to risk falling too far to recover.
I appreciate a lot of your insights, especially on characters I don't use. You do a lot of research and observation and probably have a greater grasp of game design/balance than I do. But a lot of the time it feels like you see and experience only selective attributes from each character.. You look at Ganon and see how he has improved (and he is definitely better relative to the cast, you were right there). He is likely the best character at turning stocks around in the game. You give him a percent, he takes a stock. His range is solid and his damage is excellent. But he still has poor mobility (mitigated somewhat by his movement specials), a large frame, slow attack speed, bad grab range, and what is among the worst recoveries in the game. On the other hand, you look at ROB, and see how he lost his best poking tool, how the new ledge mechanics and loss of Up-B time hurt him, how he has poor damage output and poor kill setups, and call him a bad character. Yet you neglect his potent throws, generally quick attack speed, ability to attack out of his Up-B, and access to what you openly declare to be the best attack in the game. Basically it feels like you're open to Ganon (and a few others) being good and improving but not ROB (and a few others).