One of the defining characteristics of Crossfit is how broad it is. There are so many different skills, movement patterns, exercises, and ideas to get accustomed to.....it can be very slow progress when you're working on a lot of different things at one time. You may not see great progress on any one thing very fast. It's a constant struggle to strike a balance between keeping your fitness as broad as possible, while at the same time working hard to correct weaknesses. The moment you put something on the shelf for awhile, so that you can focus on a specific skill or motor quality that is needing work, then you worry you might lose ground in the other area. To some extent this is true. The bottom line is you can't be everywhere at once, and in order to get really really good at something, you have to spend time at it. Since most of us have careers, families, kids, hobbies, etc...it becomes a challenge to create good meaningful programming. Not specializing is a two-edged sword. On the one hand it's proven to create tremendously well-rounded athletes, and on the other hand, it discourages you from getting really really good at any one thing.
It's my opinion that you should focus on your weaknesses and bring them up to speed as much as possible. This doesn't mean that you should do so to the total neglect of everything else. This would defeat the purpose. We want broad fitness, but we can maintain certain motor qualities & conditioning with reduced loads and volumes. For example, let's say I really need to improve my front squat, and work on my full squat cleans, and rack position. I'm already pretty decent at most of the gymnastics stuff, at least workably so. I'm also possess pretty decent endurance, and I'm ok with running. So what I need is more explosive power, and more strength. I'd like to have a bigger push press, bigger squat, and bigger deadlift. I'm going to assign a percentage of training time in various areas, so I can maintain fitness in areas that I'm already good at, but free up more time to spend on things I want to improve. So my plan in this example would be to cut back on running, pushups, pullups, dips, lunges, air squats etc.. Notice I said cut back, and not eliminate. This is key! Meanwhile I'm going to spend a larger percentage of time on push press, barbell squat, deadlift, and power clean. You can be as precise as you want about this, but as long as you have some kind of plan you should do fine.
The mistake I see people making is to spend too much time doing stuff they're already good at. It's easy to focus on your strengths. When you are training skills or motor qualities you're already proficient at, you're in your comfort zone, even if you're training your ass off, you're still in your comfort zone in a psychological sense as well as physically. Ultimately, this comes down to fear. I don't mean the kind of fear you associate with fight or flight, where you're frightened for your life in an immediate sense. I mean psychological discomfort, on several levels. Number one, people get wrapped up in the idea that if they back off of training in a given area, they're wasting all the time they've invested, and everything is just gonna go down the tubes. This is not true! It's an irrational fear. You're not going to lose all your gains! Backing off may in fact be exactly the stimulus they need to re-ignite the system and get primed for new gains! Remember we are just reducing the volume, not stopping altogether. You can back off of both volume and frequency and not lose much of anything in a given area. Number two, people also are just flat nervous and uncomfortable about doing something and not being an instant master at it. I'm sorry but you have to go thru the awkward phase before you get to be a swan. If it was easy and quick ....everyone would be doing it, and it would not be all that big of an accomplishment.
I love muscle ups. I taught myself to do them, but it certainly did not happen overnight. I watched crossfit videos in slo-mo and then walked outside to my rings and tried it out. Then I'd walk back inside and watch the video again to see what I did wrong. Over and over I'd implement what I saw until I finally pulled it off. Then I continued to watch more videos with different instructors so I could make sure my technique was right. So I got better at it. This took maybe a few months. I was not necessarily practicing it every day. So then I get clients who see me do a muscle up, and these are athletic guys, and they expect to be able to jump right on the rings and do it, and boy are they frustrated when it doesn't happen! My answer is: "Hey this took me a while to learn, so you're not gonna walk in here, and just jump up and do it!" This is hard stuff, and you have to have patience. You can't let fear stop you.
Stop doing what's comfortable in the gym! Do what is UN-comfortable! Ultimately a more well-rounded athlete is a better athlete at anything they do. Also keep in mind the concept of quality over quantity. Just because you're used to doing X amount of work at X intensity level, doesn't mean this is really getting you anywhere. Alwasy be willing to think outside the box and examine what you're doing objectively. Is your training getting you any measurable result of any kind? If not, then you are just a hopeless addict. Sometimes less training is exactly what you need. Sometimes you just need to get out of the gym. Is that next set really gonna get you anywhere if you're just doing it out of habit and the intensity and ferocity are lacking? I'd rather see you rest than do meaningless hum-drum work, even if it's producing a "burn." Either breathe fire or go to sleep.