Half of my teachers said you had to do med-surg for a year and the other half said forget med-surg and just do what you want. Honestly, don't listen to what everyone else says anyway. They are coming from their own experiences and only you understand your own needs and wants. Nursing is completely different now than it was 10, 20, 30 years ago and units hiring new grads usually know that they are hiring new grads.
Also, don't be afraid to apply for positions that you want, even if you think you'll never get them. My friend applied for L&D as a new grad in several different hospitals and ended up getting a position in a good hospital, even though everyone said it was impossible.
Also, don't forget that being a clinical instructor is incredibly stressful. The responsibility they are taking on is pretty serious, and I think they've earned the right to be a little testy. All of got whammed occasionally. Don't take it personally and continue making good decisions. Good luck!