Sure, but you can't really ask your client to pay for your holidays, can you? Besides, most freelancers don't have the luxury of that much vacation time.
It's up to every freelancer to lead his own business. How the business is led must not be of any concern to anyone except the individual leading it.
There are laws regarding working time.
And why would you freelance as a professional in any job, if you could do a job like cleaning toilets, which doesn't need any skill and can be done by anyone, is paid better and has less working hours plus paid vacation?
And a professional freelancer also has to come up for stuff the company usually does, like taxes, writing mails etc - which is a ton of work which also plays in the workload.
If one doesn't want to charge anything for writing mails, making his taxes, answering e-mails, doing the work, taking care of the own electricity etc. the company usually pays and let's that flow in his rates, it's that person's business.
Don't make absolute rules "what you can" and "what you can't". Leave it just as information here to consider and lead your own business as you want.
If some people love to feel miserable and can't pay for all the stuff they have to because they charge to low, it's their problem.
If some people can't get jobs because they charge to high it's their very own problem too.
