You may agree or disagree what I am saying. Anyway, this is my thought.
I, personally, don't mind my trainees to do Crossfit. I may encourage them to do it regularly.
Here are my reasons:
1. Stamina and motivation
If you always train by yourselves, you may lose the stamina and motivation. And you may take longer rest and check messages between sets. You may not pay 100% attention to your own training. You may be f*ckin around and doing nothing.
Crossfit allows you to stay 100% focus on every rep of movement. You have to do as many reps as possible within the certain time, or complete all reps as fast as possible.
Anyway, Crossfit is a competition.
If you don't like competing. Don't do it.
2. Training partners
Sometimes, you may need training partners to motivate you to push harder.
After 10 reps or heavy deadlift, if you have to do 10 more reps, it requires a lot of motivation. Your training partners can help you to go through the moment of hell.
Crossfit is brutal.
A lot of people underestimate it. It is painful.
3. Changing training environment
If you are always training at the same gym, you may get bored. I, personally, like to train at different gyms and know different people.
4. Recognizing your weakness
Through doing Crossfit, you will know your weakness - grip strength, energy system, olympiclifting and muscle-ups technique...etc
When you understand your weakness, you will spend more effort in your regular training.
Just remind you that our regular strength training is to overcome our weakness. We always focus on our weak-links rather than doing what we like to do.
Sometimes, we have to do something we don't like. Many coaches agree that bodybuilding (hypertrophy) training and isolation training can solve your weak-links with eccentric movement.
However, not many people really understand about Crossfit. Some people think they are ready to do it. Some people think they will become elite CF athletes' physique once they start doing Crossfit.
If you think you can become CF athletes' physique immediately after doing few sessions, how about doing few bodybuilding sessions, then you will become Arnold?
The elite CF athletes spend minimum 2-3 hours a day training and 12 sessions a week.
How many people can spend so much time to train like an athlete? Not many.
By the way, CF is their career, but you have your own career. We are different.
Before doing CF, please make sure you understand few things:
You must be "prepared" for each training session.
1. Can you do perfect pull-ups x 40 reps in 20mins without kipping?
2. Can you do Back Squat x your bodyweight x 20 reps?
By the way, if you don't agree to ATG squat, please don't do CF.
3. Can you do Overhead squat without shoulder injury?
4. Can you do front squat with clean grip?
5. Can you do rings muscle-ups without elbows pain?
6. Do you have knees and shoulder injury? If yes, don't do it.
7. If you cannot lift heavy deadlift with high reps, don't do it! It's dangerous!
8. Have you practiced Handstand? If not, you should practice Handstand with a coach before doing CF.
9. Forget about Olympiclifting if you cannot squat more than 100kg. Since Olympiclifting is a part of the game.
10. If you always argue with the coach, don't do it.
Your coach will repeat saying "No Rep."