I don't think either point is necessarily contradictory. To note that 60s era Trek is not something that would be regarded, in relative terms, as progressive today (if it were exactly as it was and just coming out now) as it was considered over half a century ago does not negate its contextual progressivism. Nor does noting it would not be viewed as "cutting edge progressive" today denude it of its progressive qualities. One can make the same argument about Broken Arrow (1950), a western considered quite progressive in its day (though perhaps a touch more so than it deserved--much like TOS) but one that, if released as a new film today, would not be viewed as such, save in isolated moments. The changes in perspectives over time about progressive notions form the core of the assignment I give to my students with that film (and could easily apply to TOS compared to modern expectations as well).As someone who DID grow up with it (I was 6 in 1969 and watching on NBC) - this argument above is UTTTER BULLSHIT. TOS (like current modern Trek ala ST: D and ST: P) was always seen as progressive and socially conscious/farward thinking all the way from then - UP TO TODAY.
You may not like/or watch it for that aspect - but it's been part of what has made Star Trek the phenomena it's become since 1966. To say "well, that aspect should be discarded or called out because in your opinion, it's not needed/no longer relevant <--- Which AGAIN given the current condition of society at large and the rise of bigoted/fascist groups and world leaders who support them openly - it's a needed and valued part of the Star Trek DNA.
I grew up with TOS as well (a bit later than you, I was six in 1973, when I first started watching TOS), and I'm an historian who frequently teaches American history, so I'm familiar with the point of view you're describing. But context does matter--and TOS, as is, would NOT be viewed as "progressive" nearly to the degree today (as something new) as it was when it was actually new. To acknowledge that point is not to be dismissive of TOS.