What if we try to look at all these recent incidents from some more general point of view? First of all, we should admit that
there are real problems with judgement, and if we want badminton to become more professional and more "money-attractive", they
should be solved. Namely, the most common and "hot" are the lines judgement and service. BTW, I should say that most of the players almost always violate (more or less) the service rules, especially in doubles. The usual way to solve the problems is a traditional one: more attention to judges, special trainings and seminars for them, inspections of them, etc. But I think there is more effective way - solve the problems technically, simply exclude the "man" factor at all.
As for the lines judgement, there are at least several solutions:
1) Use video-cameras. This is straight forward and already get used for many other sports.
2) Supply the courts with a sensitive strips under all the lines, connected to a PC, so that coordinates of the shuttle landing could be immediately seen on a screen by umpire and (even better) by spectators. This is more complicated and requires some RND efforts, but it is well within the possibilities of modern technologies.
What is important here - you don't need to be in a hurry when taking the decision, since the rally stops after the shuttle landing, whether it was "in" or "out". The service judgement is much more complicated: the decision must be taken immediately and cannot be corrected.
Some more considerations about the service rules. In general, I think it is unfair that tall players may serve from higher position. They already have an advantage of their height during rallies, why shall we give them one more advantage on service? Especially this is very significant in doubles (low serve), where the difference between the net height and the player's waist is of crucial importance. One can say that, for example, in tennis a tall player, when serving, hit the ball at higher point, but the rules there are simple: do what you can and if you cannot hit the ball at higher point due to your height - it is your problem (or your property). Let's compare: in badminton a small player, when serving,
can hit the shuttle in the same point as a tall one, but he simply
is not allowed to do so - because his waist is lower... What is this if not a straight discrimination???
On the other hand, the reasons of the present rules are quite clear. The service judge needs some clear marks of heights, located near the shuttle - just to compare, and the player's waist looks like a good candidate for such a mark. Then, to prevent attacking services from very tall players, one more rule was invented: the racket's head must be lower than the handle. This rule is also always violated, more or less, by all the players: initially they hold the racket almost vertically and rotate it during service so that at the instance of the shuttle's hitting the racket is almost horizontal. I think it would be better to change the serving rules and establish, for example, one meter (the actual value can be discussed) as an upper limit for the hitting point. Then we don't need the rule about "head lower than handle", and service judge don't need to guess where the player's waist is. Besides, this is more fair with respect to small players: everybody have the same upper limit. The only problem is - how to measure the height of the hitting point? I think, nowadays it shouldn't be a problem - technically it is much easier than measuring the player's waist height and then to prove him that your measurement is correct.
If it is considered to be off topic - I am sorry in advance.