well those are games from companies that really lead the pack, with their quality releases and the sheer fan anticipation for further installments of their multiple franchises... I mean sequels like street fighter.. how many street fighter 2's did we see before we finally saw a 3?.. and even the first street fighter 3 was broken (hell you could charge like 3 shinryukens and the faster you pressed kick the more damage it did... easily the most selected super art) .. it took them 3 street fighter 3 games til they finally got it right.
There is always a few exceptions.. but a majority of sequel games never really deserve to be called sequels