Yup, looks like it's going to be another one of those multi-page spanning, playstyle differences threads.
Before I go any further, I'm going to address a concept that I call the "reset button". Almost all games have a reset button. After a game of chess, regardless of who won or who lost, the game returns to its original state before a new game begins. Similarly with basketball, or soccer, or football, or tennis, the score is reset between the time that one game ends and another game begins.
RPGs also have reset buttons, but the normal assumption is that they will never be used short of a TPK or a deliberate decision to re-start the campaign. In this manner, the successes and failures of one session will influence all subsequent sessions. Nonetheless, certain events in an ongoing RPG can function similar to reset buttons. A DM who puts extra treasure in an adventure to replace equipment that was destroyed by a rust monster is performing a reset of sorts. A player who brings in a new character after his previous character died has also had a pseudo-reset. In addition, many CRPGs have "save points" which allow a player to reset a game but start at a save point instead of from the beginning.
It's obvious from the posts so far that there are several players who like a playstyle in which the reset button is hardly ever used, and when it is used, requires a restart from the beginning instead of from a "save point". They like that their decisions have in-game consequences.
However, it is possible to play RPGs differently, with frequent, progressive resets. By this, I mean that in between sessions, the characters recover from anything that happened to them at the end of the last session (up to and including death), gain a level, and their wealth resets to some baseline value based on their new level. Under this playstyle, a party can fail, sometimes quite miserably, but they recover from their failures before the next session begins. It's a playstyle that is not for everyone, and is probably suited to more "casual" players, but it's much more forgiving of when the players are having an off day.