Overall, it does seem to be a low risk procedure. The major side effect is Dry Eye Syndrome (~28% of patients, PMID:27893063), which in and of itself can be quite problematic (Sounds crazy, but DES can actually cause a lot of difficulties in daily living). But corneal ectasia is the most frightening risk factor. When the corneal flap is created for LASIK, it severs the collagen connections of the inner layer of the cornea. From what I have read, these bonds do not reform and are thus a thinning of the cornea. This thinned area is more susceptible to intraocular pressure leading to keratoconus-like deformations. Ectasia is quite difficult to treat and can cause massive refractive error.
Plus it makes it harder to calculate what lens you'll need for cataract surgery (which most people will need at some point).
The next part is somewhat speculative, so take it with a grain of salt:
LASIK is still a relatively new procedure. There hasn't been a lot of time for corneal ectasia to develop. It may be over the next couple decades there will be an increased incidence. A speaker at a 2015 FDA Ophthalmic Device Panel for Collagen Cross linking suggested that most cases of post-refractive ectasia are not reported due to the development many years after the surgery.
There was a petition by Dr. Morris Waxler in 2011 to withdraw approval of LASIK devices.