Why make them? 
When you make an appointment for any type of service you do it under the auspices of being taken care of. Even if there are others present, the appointment solidifies your right to get the service(s) you came for. For you, service is rendered without the prolonged wait if there is one. Those who came in without scheduling may have an issue with you because you proceed ahead of them. Rather they may have an issue with the entity who allows it. Nonetheless, they have to understand you took the initial effort to secure your slot.
The appointment with you
Making the appointment takes a little of your time from the onset, but it saves much more in the ending. It is your gateway to go on through. An appointment is your permission. It says to you, come on. So why make one with doctors, vehicle servicers, counselors, colleges, stylists, planners, and tax preparers, but fail to make an appointment with the destiny that is waiting? It is awaiting you to come on through. That planner, calendar, and note you depend on so greatly can only get you so much and take you so far. There is a destiny that is destined to meet you, but you need to make that appointment then put in the work to get to it.
Is an appointment with them better than with you 
No one makes an appointment then sits at home and does nothing. Unless the service is coming to you, you have to prepare to get to it. That means you have to shower and clean up, choose your outfit, get dressed, and leave where you live. The order may be different but the concept is the same. Consider all of the prep time you put into making an appointment with someone else. What makes them so much better than the future you? The answer should be nothing. If the answer is nothing, why is so much put into them, and so little is put into you? Reevaluate your importance to yourself. You may be shocked to see what your honest answer is.
– The Life Teacher, Author and Mental Fitness Coach, Worldwide Watkins