I do tire sometimes of those who say "if you give an inch of extra legroom fares will have to double".
Firstly few flights operate at the sort of high load factors where the lesser number of seats (and it isn't that many that would be stripped out) would make any difference to flight revenue. It seems unnecessary to be squashed in between empty seats.
And major airlines will tell you that the mainstream revenue is made on the premium classes anyway, with the economy passengers making no financial contribution. Frankly I doubt this (why else provide 75% of your cabin space for the useless patrons) but that is the standard line.
The A320 has a cabin 6" wider than the B737, usually translated into 1" extra width per seat. But I haven't noticed that the extra drag the wider cabin entails leads to fares all being double on A320 operators compared to those with B737s.
I was also, like many transatlantic passengers, surprised that American Airlines took away MRTC, as during its time there were many, many AA passengers who commented on it and gave it as a reason to select AA. There was extensive justification before it was introduced which all seemed to be thrown away. It really did make me think that policy decisions like this are taken in boardroom battles between differing opinions, with the facts being presented through selective "research" afterwards to fit the prevailing view. It was also noticeable that MRTC coincided with a financially good period for AA, and since they reduced the legroom again they have never made anything like the net income.
Given that seat pitch is normally measured between seatbacks it should surely be described as "shoulder room". But real legroom, under the seat ahead, has on a number of long-haul carriers been severely impacted in recent times by the imbecile who decided that the new AVOD video boxes for each seat row can be bolted underneath the seat row, right where the person behind's legs used to go, as if they somehow would not notice. It is usually only one seat per row that suffers like this, but different carriers have adopted different positions for it.