Want to name some of the remasters? Are these all LPs, or is it mixed between those and CDs?
Most speakers at the time sounded somewhat similar, if you compare those made in various regions- East Coast, West Coast, German, British, Scandanavian, Asian etc had a 'sound' that made them different. Japanese speakers often were referred to as 'boom/crash' because the midrange was lacking. Micro-Acoustics made speakers with almost no midrange at all, yet they made some nice-sounding cartridges.
That allowed studios to use the monitors of choice without people hearing a huge difference, especially when they used small ones to find out how it sounded through a car radio (if you don't think that was a consideration, look it up).
Fast forward to more recent times and the differences are glaring- many LPs that were very popular sound like absolute garbage.
BTW- unless someone was a huge star or also the producer, the mastering engineer (in name only), producer and engineer determine how it will sound and where people are located. Doesn't mean they knew/know what they're doing, though.