It's patronizing, but I wouldn't consider it crossing the line to bullying or abusive. I read it as someone who considers themself to be in a position of experience and authority counseling a newcomer on the rules of the road. Perhaps the "inner voice" that reads that text to me on the page differs from the student's inner voice?
It's hard to discern tone from text on a screen, and easy to attribute meaning to actions that did not carry that intent.
Anything that starts with "Thing is" or a similar type of sentence ("In reality", "Here's the deal", "With all due respect", etc.) is condescension. There's no other way to take it. Especially when it's followed up by a "you don't get to make that decision".
And any time you start off by being patronizing you aren't actually trying to advance your argument or teach somebody but rather trying to belittle the other person.
It's hard to discern tone from text on a screen, and easy to attribute meaning to actions that did not carry that intent.
Disclosure: I'm a privileged white male.