Well, the requirement for a SI for those specific conditions is not really the fault of the FAA. It's required by the statute as passed by Congress. Here's what the statute ("FAA Extension, Safety and Security Act of 2016," Public Law 114-190) says/requires:
"(e) SPECIAL ISSUANCE PROCESS.—
(1) IN GENERAL.—An individual who has qualified for the
third-class medical certificate exemption under subsection (a)
and is seeking to serve as a pilot in command of a covered
aircraft shall be required to have completed the process for
obtaining an Authorization for Special Issuance of a Medical
Certificate for each of the following:
(A) A mental health disorder, limited to an established
medical history or clinical diagnosis of—
(i) personality disorder that is severe enough to
have repeatedly manifested itself by overt acts;
(ii) psychosis, defined as a case in which an individual—
(I) has manifested delusions, hallucinations,
grossly bizarre or disorganized behavior, or other
commonly accepted symptoms of psychosis; or
(II) may reasonably be expected to manifest
delusions, hallucinations, grossly bizarre or disorganized
behavior, or other commonly accepted
symptoms of psychosis;
(iii) bipolar disorder; or
(iv) substance dependence within the previous 2
years, as defined in section 67.307(a)(4) of title 14,
Code of Federal Regulations.
(B) A neurological disorder, limited to an established
medical history or clinical diagnosis of any of the following:
(i) Epilepsy.
(ii) Disturbance of consciousness without satisfactory
medical explanation of the cause.
(iii) A transient loss of control of nervous system
functions without satisfactory medical explanation of
the cause.
(C) A cardiovascular condition, limited to a one-time
special issuance for each diagnosis of the following:
(i) Myocardial infraction.
(ii) Coronary heart disease that has required treatment.
(iii) Cardiac valve replacement.
(iv) Heart replacement."
Pretty much exactly what's in the FAA final reg. If you want to check it out yourself (and risk your eyes glazing over), it's Section 2307(e) of the law, which I've attached below (beginning on about the 31st page). So blame your Congressmen and Senators.
On the positive side (I think), both the statute and new reg say this about the cardio SI:
"(2) SPECIAL RULE FOR CARDIOVASCULAR CONDITIONS.—In
the case of an individual with a cardiovascular condition, the
process for obtaining an Authorization for Special Issuance
of a Medical Certificate shall be satisfied with the successful
completion of an appropriate clinical evaluation without a
mandatory wait period."
This is Section 2307(e)(2) of the statute. It's also Section 68.9(b) of the new reg. Possibly a lower bar for the SI than before?
I'm no expert in any of this. Just pointing out what I see. I hope this helps.