Last things first:  No one can assess the relative suitability of an
apicoectomy vs. an implant without specific knowledge of your clinical
situation.
    As to the substance of your question--when to restore a tooth that has
had a root canal and is still symptomatic is always a dilemma.  It is
true that sometimes teeth can be symptomatic for a long time--even
without any other indication (on x-ray, for example) that there is
anything wrong.  If restoration is delayed too long that incurs a risk
of re-contamination of the root canal system, to say nothing of fracture
of the non-restored tooth.
    However, I am personally hesitant to place a post in a tooth that is
symptomatic--on the chance that something like your experience happens.
 In any case, the number of posts being placed is diminishing, as the
place of posts in restoring endodontically-treated teeth has changed.
If I feel some kind of restoration must be placed, I will place a bonded
core and a temporary crown which can be removed if necessary.  If I feel
I must proceed with the permanent crown I will try to insert it with
temporary cement so that it may be removed if necessary.
    If your dentist had done this, it would have been easier to re-enter
the tooth to re-treat in the conventional manner, without damage to a
new permanent restoration.  However, we are presuming here that given
the choice the endodontist would have opted for conventional retreatment
rather than an apicoectomy.  This is not necessarily a valid
presumption.  It may be that knowing the tooth as the endodontist did,
the apicoectomy may have been the treatment of choice anyway--for
instance if he/she knew that there was an impassible canal.  In any
case, most posts can be removed--not all, but most.  So the placement of
the post--while inconvenient--does not necessarily prevent non-surgical
re-treatment.

Hope this helps,
Steve