I beg to differ.
Maybe you're in an urban area that stresses the trannies a lot more than what we experienced.

My first brick went over 400K miles on what I presume was the original tranny - I bought it at 117K mi. The only service done on it in my ownership was fluid change, and rear tailhousing bushings + seals. Mixed city/highway.

Our second brick went over 300K miles, no tranny service.
#3 & 4 are currently at about 255K and 205K miles respectively, no tranny service other than flushing fluid.
#5 ('90 244): miles unknown due to broken odomenter at 197K mi.
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Sven: '89 245, IPD sways, electric rad. fan conversion, e-codes, 28+ mpg - auto tranny. 850 mi/week commute. '89 245 #2 (wifemobile). '90 244 (spare, runs).