Baldy,
Good question. Here are some good reasons not to get a transplant:
1) If your expectations are too high. If you are hoping for a head of hair you had in your teens you will be disappointed.
2) Your supply doesn't meet your demand. Can your donor area can provide enough grafts for a substantial cosmetic improvement?
3) You have diffuse thinning. This is where the thinning exceeds beyond the typical norword pattern and sometimes into the donor region.
4) If you don't have the long term commitment for multiple transplants. If you get one you will probably need another.
5) You don't take finasteride. Granted, there are some decent looking HT patients who are not on the meds. But I believe they are playing with fire!
6) You don't like scars. My scars don't bother me but for some strip patients they do.
7) If you are not educated about hair transplants. Know what you are getting into.
There are many other reasons why you shouldn't get a transplant but they all depend on the factors the patient brings to the table; i.e. physiologically, mentally, emotionally, financially, etc. It's a long journey that you can't possibly overestimate before you start.
For me, I'm glad I got transplants. Yes, I'm not a finished product yet but SMG has me on the right track. If you do decide to get a HT the most important thing is to find a clinic you completely trust.