Your idea is good, but your arguments dont have some minor flaws.
(Not supposed to be an insult, but it definitelly weakens your points.)
Here is some constructive criticism:
Slippery slope
“Start with one config, you end up with a mess of interdependent settings… leading to bugs.”
Claims a small step (one option) will cascade into chaos without showing a causal chain.
Straw man
“Eternal reviews… perpetual dependency…” / “Is ‘mastery’ even needs eternal extension?”
Recasts an optional, opt-in “Master+” as enforced “eternal” reviews, then attacks that caricature.
False dilemma (either/or)
“If the goal is true proficiency, subtraction might be better.”
Frames it as subtract features or lose simplicity, ignoring middle paths (for example, advanced, off-by-default toggles, sane defaults).
Hasty generalization / overgeneralization
“More flexibility… often masks a lack of strong design choices.”
Broad claim about “options” from no data about this option’s usage, design quality, or outcomes.
Faulty analogy
“Sharp knife vs Swiss Army tool that does nothing.”
The product isn’t analogous to physical tools in a way that supports the conclusion; the analogy substitutes for argument.
Appeal to fear / loaded language
“Bloated system that’s harder to evolve,” “diluted core experience,” “tutorial hell.”
Emotionally charged terms used to bias judgment without evidence.
Post hoc / false cause (unsupported causality)
“Add options → mess → untested → bugs.”
Bugs result from process/QA, not intrinsically from the mere presence of a toggle; causation isn’t established.
Begging the question (assuming what’s at issue)
“Options aren’t free. They add cognitive load and technical debt.”
This is the contested premise; it’s asserted, then used as the conclusion’s basis without showing that this option meaningfully increases either.
Anecdotal evidence / argument from personal incredulity
“I’ve used this site for over five years… if I have to ask… how can a new user…?”
Personal difficulty is treated as evidence of general unusability.
Cherry-picking / selective attention
Downplays mitigating facts in the announcement (opt-in, off by default, parked in “Advanced,” explicit caution about side-effects) while emphasizing worst-case outcomes.
Equivocation / ambiguity around “mastery”
Treats the product’s specific “Master”/“Master+” labels as if they must track a philosophical notion of “true proficiency,” then argues from that shifted meaning.
Non sequitur
“Eternal reviews for rare vocab? … risks anchoring people instead of immersion.”
Even if some users keep reviews longer, it doesn’t follow that the system as a whole prevents immersion; optionality breaks the link.