I respect Steve, I do not follow him closely, but in previous videos of his that I have seen, he seems to come from a position of experience and research. In this video he seems to come from a position of speculation and assumption. There are plusses and minuses to everything and the only opinion that matters is yours.
With such lousy room and not really any options for acoustic treatments, a few have suggested that active is possibly a cure-all for this?
The only way an active speaker can help with a lousy room is if they give you access to adjust the parameters in the DSP to allow you to tune the speaker to the room. Active speakers with ARC is one way of adjusting the parameters. Out board DSP units like those from MiniDSP, DBX, XTA and others, allow you to adjust the parameters via built in interface or computer or both. You can also adjust some of the parameters with out board analog e.q.s
SG states about ¾’s of the way through his rant that "as the speaker ages you get stuck with the out-of-date DSP”
Any technology will become out of date as it ages. DSP in a lot of cases can easily be kept up to date with software updates downloaded from your computer.