a weak point is a ammo rack or fuel can, or a vent .
in wot you cant directly aim at weak points you can only get a % of luck in hitting moduals.
to put simple:
WOT is mostly luck there not much skill involved just aim when green and shoot then hope you get lucky hit which damages certain moduals.
point is you cant aim at weak spots and get moduals damaged based on hits, the only exception i know of is tracks and possible gun on the jagpanther which is bugged and allways gets destroyed on the first hit thanks to autoaim bug.
but you cant say "i going to aim at his fuel/ammo rack" then if hit blow him up or get him on fire this just doesnt work like that.
I agree that you cannot aim for an ammo rack and always hit it, some of it is luck, but you can aim at the spot that the ammo rack is in and your chances go way up if you penetrate to damage the rack. If you do not aim for spots where modules are you cannot damage them can you? It is still a very good idea to aim for "weak" spots. Currently before the patch (6.2) is applied I am for the gun on a KT all the time with my T29 and almost always penetrate and in enough instances do a critical (take out the gun?), so I disagree when you say it does not take skill. What side is the ammo rack on for KT or IS, where is the driver located on different tanks, skill is involved for aiming for them and knowing where to aim. It is still chance to actually hit it because of tank movement and inaccuracy of the gun. But skill whether it is knowledge based (know where to aim) or twitch based (aiming at the right spot from distance) is still skill.