That is a definate maybe

Got a letter from a student today:

Dear Dr. WiseWoman,

thank you for all the information you gave me about the bachelor's thesis yesterday.

I had asked other professors if they had interesting topics, but they didn't answer my emails, so I committed to doing my thesis with you. But today Dr. X finally answered his emails. He doesn't have time until next week to meet with me.

I know that I promised to do the topic "Advanced Indecisiveness" with you. And this decision stands. I just wanted to let you know that I may change advisors, after speaking with Dr. X next week.

I am sorry about this, but after all it is my Bachelor's thesis and I want to choose a topic that is best for me and my professional career. I hope you understand.

Sincerely,
Stu Dent

My answer:

Dear Stu,

Hmm. I am confused.

Is this like: yes, I will come to your party, unless there is a better one that I get invited to before then?

Choosing your adviser and your topic is a very important task, and you had 5 semesters to do so. I only take a few students so that I can advise you properly. If you switch at the last minute, I may have told someone else "no" who could now work with me.

This is not about you choosing which pancakes to have for breakfast. I also get paid by the amount of people I advise. If you drop out at the last minute, I have to teach an additional class next semester to make up the difference.

I offer topics in which I feel that I am qualified to advise you. If you are not interested in my topics, then you should say so. After all, after you committed I contacted the third party interested in this topic, introducing you to each other. How do I explain to them that you now want to do something else? Scared off in a day?

I feel like the host trying to plan for a party, but with so many maybes doesn't know how much food and drink to offer. Why didn't you tell Dr. X: Sorry, I have already committed to write with Dr. WiseWoman? What would Miss Manners think?

So no, I don't understand.

Sincerely,
Dr. WiseWoman

Now, this is the second student in two days to send me letters like this. I guess they all finally got emails from colleague X. I've been teaching at university since 1993, this happened with one student last semester and two this semester (to date). I find it very strange - is this just the "me" generation, or am I getting too old and crochety?