Well, here is an analogy I just thought of, from my own professional life. I supervise the research work of many people. I am not self-employed but work for an academic institution where most of my duties are research and also some education. The experimental research work we do can be very hectic, unpredictable, and takes long hours - definitely not 9-5 and we often work on weekends. I used to spend lots and lots of weekends, holidays etc in the lab when I was younger and did the manual stuff myself. In my current position I no longer do that but have the responsibility of running multiple lines of research, supervising, management, administration, lots of writing etc. At this stage of my career, I don't want to be in the office and available for meetings just anytime, eg. when my students please. I want to have a balanced life and be able to get a lot of work done from home because I can afford it. But of course people constantly try, I am being pursued for last minute meetings and deadlines, look at this, look at that, the members of my team often have all kinds of issues (including personal) they need me for, etc etc. I try to do my best to be accommodating but have learned from experience (the hard way!) to draw realistic, reasonable boundaries in my time and availability otherwise not only I go crazy but the work won't be effective either under constant stress, unpredictable demands, and for me not being able to relax and do things unrelated to work. I don't work 9-5 and never have but I am also not willing to schedule/respond to requests after 7-8 pm and on weekend nights and vacations unless it's absolutely crucial. I now tell people this when they express an interest to work with me and they can choose whether I am the right person or not.

Of course service providers and people in helping positions should be understanding and accommodating, but I don't see why anyone should sacrifice their lifestyle of choice if they can make that lifestyle work. It probably would not be of help anyway if the professional had to live in a way they don't like or want, I think that would inevitably affect the effectiveness of their work performance. There are enough chaotic and unmotivated therapists, as it is evident on this forum, I think it would not be a good use of our time and money to be able to see a T whenever we want but with even more useless or harmful work ethic and style.

I am much more error-prone and irritable if I have to work in ways I dislike beyond a few weeks. I don't see why therapists would be exempt from this. It's more about consistency: if they initially tell a client they are willing to schedule early/late hours and weekends and/or are flexible, they should be able to stand up to that promise. I think this is quite similar to the questions around between sessions contact that is frequently discussed here.