Does he really says minority should rule majority instead 
If the majority cannot override the minority, it doesn't follow that the minority is ruling anyone.
The minority is just enforcing the rules that the entire network consented to; they aren't forcing anything on anyone. Changing the rules involves establishing a new consensus.
Now lets get back to the topic, Bitcoin Core 0.12 introduced very controversial feature RBF (Replace by Fee)
RBF wasn't controversial. Who complained about RBF besides a handful of muppets on r/btc and bitco.in?
It's a fully opt-in protocol, meaning that users who care about unconfirmed transactions can continue to not use RBF. RBF transactions are clearly flagged in the nSequence field, so developers don't really have an excuse for ignoring it. Many programs and platforms that trust unconfirmed transactions already regard low sequence numbered transactions as suspect and ignore them until they confirm.
Why, specifically, was it considered controversial?
Quote
Was the opt-in RBF pull request controversial?
Not in the slightest. After extensive informal discussion stemming back months, the PR was opened on October 22nd. It was subsequently discussed in at least four Bitcoin development weekly meetings (2015-11-05, 2015-11-12, 2015-11-19, and 2015-11-26).
In the PR discussion, 19 people commented (including people working on at least three different wallet brands) and 14 people explicitly ACKed the change, including at least one person who had been very outspoken in the past against full RBF. No clearly negative feedback was provided in the PR (or elsewhere that we are aware of) while the PR was open.
https://bitcoincore.org/en/faq/optin_rbf/Not in the slightest. After extensive informal discussion stemming back months, the PR was opened on October 22nd. It was subsequently discussed in at least four Bitcoin development weekly meetings (2015-11-05, 2015-11-12, 2015-11-19, and 2015-11-26).
In the PR discussion, 19 people commented (including people working on at least three different wallet brands) and 14 people explicitly ACKed the change, including at least one person who had been very outspoken in the past against full RBF. No clearly negative feedback was provided in the PR (or elsewhere that we are aware of) while the PR was open.