How many Tauruses did GM put out in that decade? Where was GM's Continental Mark VII, or Town Car, or FWD Continental, or ninth generation Thunderbird, or (indeed) eigth generation Thunderbird?
Now how many Citations did Ford dump on an unsuspecting public? How many HT4100 cars was Lincoln selling? How many Cimarrons did Lincoln throw together? How many Chevettes or Le Mans did Ford sell? Aside from the seventh generation Thunderbird and its brethren I posted above, where are all of Ford's terrible attempts at downsizing that were unmitigated sales disasters? Where are all of Ford's diesel engines? Some of Ford's laziest (Escort, Tempo, EXP) easily matched some of GM's laziest; but I can't think of anything immediately that approached GM's worsts.
And where were GM's high points? The GMT 400 pickups? The W Body Grand Prix coupe? Chrysler, for all of their foibles during the decade, had the Caravan and (after buying it from Renault) the Cherokee; plus they at least had mastered the art of squeezing every penny they could out of their entire lineup and tied up with Mitsubishi for what they couldn't do.
Maybe let me ask you a bit differently: GM entered the decade after three wildly successful corporate downsizing attempts of an unprecedented scale and a fourth one imminent with absolutely massive anticipation.
Ford and Chrysler entered the decade teetering near bankruptcy, with the latter only surviving by the skin of its teeth. AMC entered the decade as a shill to sell crappy French cars.
Ford and Chrysler exited the decade with so much money that they had already started wasting it on vanity purchases. Most of Ford's model lineup was either brand new, imminent to be replaced or so much better than the domestic competition anyway that they didn't have to worry about it. Chrysler basically got their entire 1990s lineup paid for them by Renault, if not developed; and once Lido was thrown out they started debuting. AMC didn't last the decade, but everything they were working on went towards Chrysler's 90s success.
GM exited the decade so disastrously that they had entire platforms of cars shared among multiple brands, totaling literally more than a dozen models, that dated to the early/mid 1980s but couldn't be substantially updated until at least the middle of the 1990s.
Why do you think that is, if none of the domestic brands were notably better than the others?
Actually, no. Your point seemed to be that someone saying something as benign as "'80's era Fords were okay, unlike the slushies from GM and Chrysler", something a period publication would probably agree with as the decade went on, was "blatant fanboyism". You stomped in with such a laughable overreaction to a mild statement of preference that even ignoring how much stupider your original counterpoint of "All American cars were crap in the '80s" was, I have to legitimately wonder what knowledge you thought you were imparting at all.