It's a cheap and effective drug that has minimal side effects as long as you follow the instructions on the packaging. Pretty much all of the alternatives are worse.

Ibuprofen is usually rated to be on the same level (damaging your kidneys rather than your liver during long term use) but from what I've read I believe the potential side effects are more extreme (i.e. the elevated stroke/heart attack risk).

Using any pain medication for prolonged periods of time without consulting a doctor is dangerous. Many people do it, and most are absolutely fine, but when things go wrong, things go terribly wrong.