If these a/c were so unsafe, then AA
would dump them or their insurance carrier wouldn't insure them any longer or at a much higher premium. It's all about the $$$'s. AA587 was one of the few cases where possible structural failure contributed to an aircraft crash in many years. The pilots reacted very well and correctly in this incident, probably something well rehersed in training/simulator time.
The A300's are workhorses for AA
on critical routes, have advantages over similar a/c due to their cargo capacity, are probably long paid for, reasonable on fuel use, pax get good service, and even if maintenance hogs, still cheaper than new/newer replacement a/c. (AA
cannot afford replacements right now I suspect) Yes, this is a serious incident, and probably due to something that can be figured out, and corrected in the future. Maybe a loose or too tight wheel nut, maybe a bad wheel, maybe brakes hung up a bit on landing, There can be a number of reasons. NTSB will have the answer soon enough and I suspect the AA
mechancs already done what needed now and considering if need to replace connected parts.