We all have different things that we aren´t very good at. It can be cooking, singing, running, sewing, maths or something else. The same thing applies to guitar playing. Maybe you´ve got a great picking technique but a bad legato. Or maybe you know lots of scales but don´t have that many chords under your sleeve. When people are bad at something, let´s say sewing, many claim that they aren´t very talented in that field and by that legitimizes their lack of knowledge. It´s of course just a sweepstake and a reason not to try to get better - "I have no sewing talent, so what´s the point of practicing it?". When it comes to guitar playing, you more rarely hear this, but it sure does exist on some level. Maybe just in the back of your head where you´re constantly undermining your skills.
What it comes down to in the end is lazyness. If I´ve got a good picking technique it´s often more fun to practice this than to deal with my poor legato. But if you´re already good at picking, why make small, small progress here, when you could make big progress with your legato if you just put down the same amount of time practicing it? Yes, of course it can be a good thing to make a niche, to be specialized in something, especially today when many people makes a career of being extremely good at just one thing. But it´s always good to have a broad knowledge, especially on the guitar. To be able to play more than one style of music, to have several different techniques under your belt, to be great at both rhythm playing and soloing. Some people would say that it might kill your pop career, but I don´t think that´s true. Let´s take a mailman for an example. What if one mailman is really good at delivering the mail but pretty poor when it comes to sorting the mail? Yes, he will be fast when he is out delivering, but it will take him long time before he can do this because he is so slow at sorting the mail. If he´d put down some work on his sorting he would be able to get out on his delivery round way earlier, and could by this get home from work faster.
Another example can be a triathlete, an athlete whose competitions is made up of three different elements: swimming, cycling and running. Of course every triathlete has a speciality, but the trick to be really good at this discipline is to be as equally good in swimming, cycling and running. If you´re a really poor swimmer but a great runner, you might run in a few places that you´ve lost in the swimming, but you will surely never win a race with this tactique. What you do need to do is to cut back some hours every week on your running exercise (a field where you already are good) and instead use this time to focus on your swimming. Don´t cut out all the running, you still need to train this to maintain your capacity, just don´t put in too many hours here when they´re needed somewhere else. The same thing of course applies to guitar practicing: if you have a good knowledge of chords, don´t put too much of work here when it´s needed more in other fields like sight-reading or alternate picking. The hard part isn´t knowing what you´re bad at, the hard part is to deal with it and practice it to get better. It will sometimes be hard to do this, but in the end you will benefit from this model. Don´t practice too much on what you´re already good at, put the work in at fields where you netheed to get better.