Not necessarily. Distributors and production companies sometimes cut perfectly good scenes from a film so that its running time is short enough for them to squeeze in an extra cinema screening each day letting them make more money. This also allows them to use the advertising hook for the dvd release of saying that the dvd has 'scenes not shown in the cinema'.
Also, some films, such as (the admittedly troubled) Highlander II were given different edits in different countries due to the fact that so many companies had a slice of the pie and bickered about what the final film should look like. There are versions that run at 89, 100 and 109 mins in length. I certainly don't think that the 20 mins missing from the 89 min (British) version were scenes that were not good enough for the film. IMHO that particular edit is the worst of the lot.