Yeah, some traders finds it more conducive to trade just maybe twice or thrice a week, which what ever profit they make with those time period, they would be okey with it and even if they experience losses, they will try again next time. Being successful in training require the trader to be principled with every trading strategy they are using and also respecting their own rules of trading. For example, if you say you are going to take 2 trades in a day, don't exceed two, if you said you will take profit at +10% for the two trades, don't exceed it. That's being principled and obeying your own rules for trading.
If your are professional traders, you must understand how many times you need to trade daily/weekly. You must also understand how much profits to take, and what the right strategy to apply. These things should be determined through some analysis, so you won't decide it carelessly. However, sometimes beginners have no idea about determining these things because they still have lack of knowledge. So, whether they want to trade 2-3 times a week or even everyday, they have no certain rules or principle in trading. That's why knowledge is the basic thing, you can determine everything properly if you have good knowledge.
Sure, we must stick with our principle/rules. It is something crucial because it can avoid greedy. Once we fail to obey the principle/rules, we may end up with losses due to unrealistic targets. By the way, since we must take profits in a short time, we shouldn't set too high targets. Raising 10% is enough to take profits. It is quite different than holding for a long term that we can set a high target because the price change can be very significant.