Ok if you want a serious reply, let's get started.
First off I'll address the realism concern, just to get it out of the way.
1. Hitting through objects allows a pikeman to simulate being able to actually maneuver the pike in a sensible way around obstacles. This means a little pile of debris isn't a blockade stopping a pikeman from being useful, it allows piking over low walls, and allows us to simulate formations with shieldwalls. Yes, it's unrealistic to be able to stab clear through large objects, but without this ability, you lose the previous abilities too. This would just swap where the pike is realistic and where it isn't, NOT make it totally realistic.
2. Being able to thrust when an opponent is past the head of the pike simulates being able to grip it at different lengths, as you can with a real pike. When using a real weapon, your hands aren't glued at certain points, you can shift them. Seeing as warband has no mechanic for this, being able to hit along the shaft simulates it.
3. This game has a hundred other things that are equally unrealistic or even more so. Let me just list some here before some idiot says it's all realistic.
-Horses can run you over, dealing minimal damage, and continue on at 99% full speed.
-Crossbows can be reloaded very rapidly
-you don't die when hit by a bolt or arrow even in low armor
-Greatswords can cleave tincans in two 3 inches after they start swinging.
-You CANNOT spin and overhead or thrust in real life at all.
-You do not have 4 attack and block directions in real life
-You cannot spam endlessly in real life without becoming dead tired
-Nighttime in a medieval setting would be pitch black save moonlight and torches.
-Full plate can shrug off most anything, yet in c-rpg you can kill a tin can in just a couple hits with a 1 handed pick.
-In c-rpg being hit by a sword or arrow has no hindrance on your performance save a little drop in your health bar.
-You don't bleed in c-rpg.
-You respawn when killed.
-You can jump 5 feet in the air.
-Horses are stealthy
Ok, now that that's over let's address the balance issues.
1. It is hard as balls to hit someone with the tip of the pike if they don't just walk into it like an idiot. The tip is TINY, and with c-rpg physics it is NECESSARY to wiggle in order to get a good hit 80+% of the time. Making the shaft not deal significant damage is a HUUUUUGE nerf. Especially considering that we can't change where we grip it, there is only a tiny tiny range that we can hit with the tip.
2. People keep saying these nerfs will somehow make the pike into a support weapon more than it is. I call bullshit. If the pike can't wiggle around teammates then it becomes only useful as support in VERY small skirmishes with 3-4 participants. In any larger battles, it becomes totally (COMPLETELY) useless as a support weapon. Additionally, if it can't hit around high walls, then it can't hit around low walls, and that means it's only useful on flat ground (it's already useless on slopes due to shitty ground hitboxes.).
3. Now I didn't see anyone mention it in this thread, but I'll go ahead and address it anyway. Jumpspins. Yes, they are unrealistic as shit. However, without them having a Pike and getting charged by a spammy bastard means the only option the Pikeman has is to die. Don't tell me "Oh just pull out your sidearm." YOU try doing that after being thrust stunned for a full second, and then having some fool with a giant sword swinging at you.
I have yet to see anyone suggest a way to make the pike more realistic without making it useless. If you want to try and fix it, go play it for at least a gen then come back. Very VERY few people have any idea how the Pike works, and this leads to 99% of suggestions around it making it totally useless.
Before you suggest a way to fix a weapon, play it first so you don't just say something foolish. Please.