The Soyuz FG used for manned ISS trips has a 100% success rate...

There is and has never been any signifant ISS space science, research, exploration which justifies even 1% of it's astronomical flying pork costs...

Private industry, for the most part, flatly refused to participate in the KSC study for fear it would reflect unfavorably on their products.
===
a snide but unsupported attribution of motive..there are many other possible reasons.

In July 2011, ULA signed an unfunded Space Act Agreement (SAA) with NASA whereby the space agency would provide ULA with technical knowledge from its human spaceflight programs
==== ==
Federal Agency Nasa promised America a 'cheap, safe, reliable access to space' $7 million per flight Shuttle... then delivered a $1.6 billion per flight boondoggle which killed 2 crews and had chronic multi-year service outages... the most unaffordable, dangerous, unreliable space vehicle in history... then Nasa blew $20+ billion on it's miserably failed/cancelled Constellation... now Nasa struggles mightly to re-create the archaic Saturn/Apollo technology it threw away 40+ years ago...
Nasa has blown $500 billion on US manned space flight since Apollo ended without getting a single American beyond low earth orbit, leaving itself incompetent/incapable of crewing or even resupplying our own space station...
the thought of anyone wanting/needing technical knowledge from Nasa is laughable..

The Nasa 'flags and footprints' model of Big Frigging Rockets led to the demise of the Apollo project, and the following 44 years and $500 billion of Nasa US manned space dead end boondoggles and futility.
Von Braun's 'Earth Orbit Rendezvous' EOR plan utilizing medium size multi-purpose boosters and on-orbit module connectioin would have gotten us on the Moon by 1967 for less than half the cost of Apollo.. and left an affordable space infrastructure which would have supported lunar colonies and Americans on Mars for far less than what Nasa has expended without getting a single American beyond low earth orbit.
The Nasa BFR approach skyrocketed the Apollo program cost because of the unsustainable Saturn V booster costs and because the Nasa insistence on a single BFR launch imposed Apollo stack weight constraints which cost $billions to solve...
Nasa's Saturn, Space Shuttle, and now SLS will all cost over $30k per pound to LEO...
SpaceX Falcon Heavy will cost less than $750 per lb to LEO.
Combine SpaceX economics with on-orbit module connection and fueling, modular, affordable, sustainable, reusable infrastructure, and an American Mars mission is easily within reach for many American businesses or foundations to finance... or even crown funding.
The US space program is too important to be further entrusted to our bloated, pork driven Federal Govt and Nasa.

Each Apollo mission risked failure which would have cancelled or delayed the project past the decade deadline..why go all the way to lunar orbit, take all that risk, but not try to land... .. The question is why didn't Apollo 10 land on the moon?
The answer is that the A10 LM was just too heavy and the software and comm systems were still not ready.
The A11 LM was the first one light enough to land and return to orbit.

a super heavy lift vehicle makes everything a lot simpler and cheaper to do
====== =
a super expensive, unsustainable, unaffordable (e.g. Govt/Nasa) heavy lift vehicle makes nothing cheaper or simpler... it does waste taxpayer $billions and resources, destroy/prohibit worthwhile programs, sap the life from taxpayer funded US space.

fuel is fungible... BEO missions easily support separately launched/linked modules..
SLS and Orion are more Nasa shameless earmarked boondoggles...
"All that is necessary for the triumph of evil is that good men do nothing." Edmund Burke

Any private enterprise must recoup all development costs, prorate them over all units produced/launched...
The author's 'ground rule' to ignore development costs and ".. Arguments based on cost of launcher development;"

Make the remainder of the article nonsensical.... apples to oranges..
There is a fixed US space budget, cost does matter, there is such a thing as fair and reasonable cost accounting... but Nasa/SLS proponents want to, must, ignore, pervert any accounting including Nasa's massive fixed deadwood overhead and development costs..

The true cost of SLS launches (if any) will be a minimum of $2-3 billion per launch,..likely much more.

"...it will have a huge advantage over the Falcon Heavy. "

Only if cost is not object. Unfortunately it is...
==== ==
'Unfortunately'????
Remember that it is OUR MONEY we are talking about... ours plus our children's, with these Democrat Govt deficit borrowing....stealing from our children...
The Govt wasting $billions on the unsustainable, unaffordable, unnecessary SLS/Orion is criminal.

So.... GWB created the COTS program and commercial space over strong Democrat objections.....
then the super majority Democrat House and Senate authorized SLS/Orion, signed off by Obama and Obama's Nasa head... second to Nasa's primary goal of 'Muslim Outreach'...

yet it is all a few powerless Republican Congressmen's fault...
You drink the Kool-Aide.

I'm actually feeling pretty positive at the moment. In spite of the SLS tax, we're making significant progress and I think we'll be surprised where we find ourselves in a decade or so.
=== ===
How disgusting to be taxpayers encouraged that our hard earned $billions confiscated by our Govt are wasted, but not entirely blocking private sector advances...
We should loudly demand better... I think the best solution would be to downsize Nasa back to NACA levels, and directly fund private enterprises like SpaceX and Caltech's JPL without the greedy, incompetent, pork driven Govt bureaucracy.