[SamBam]

I feel like others have probably replied well enough, but to add: you seem to be under the impression that they are only "too fast" because modern TVs play them at the wrong frame rate. On the contrary, contemporary audiences in theaters also saw them move "too fast."

This was a result of both the mechanics of the time, and the style, as other people have posted.

"Speed correcting," therefore, is simply an attempt to view these at natural speeds, even though this may not have been the expectation (or intent) of the filmmakers.