Not to mention that it's only recently that Blender has become bearable, even if 3dsMAX,etc is ancient those kinds of tools were often used in the past and Linu

Not to mention that it's only recently that Blender has become bearable, even if 3dsMAX,etc is ancient those kinds of tools were often used in the past and Linux was a kind of no-starter. Also since intros were size-limited you kinda needed control of your pipeline to achieve the smallest size of the _binary_. For a 4k intro different compilers could produce different sized binaries, the .exe compressor crinkler mentioned above does some "function-order-randomization" to improve compression by a few bytes by having the correct ordering of data/functions so just running a slightly different version and/or not long enough could fail to produce something below 4k.