thanks @MGleason!
flagging

Flagging is a skill. The op obviously doesn't have the skill to flag, or he wouldn't be griping.
Flagging is unfair. Winning with chess skill alone is the only right way to win.

Time management is part of chess skill.
Put it this way: if there is no clock, if you spend an hour on every move, you should almost always beat someone who is just as good as you if they only spend five seconds on each move. You're spending a lot of time thinking about the position to find the best moves. But that wouldn't mean you were better than the other person, or that you had more chess skill. It would only mean you were taking more time.
If you get flagged in a winning position, it means you spent too much time finding good moves instead of saving some time for later in the game. You have a winning position because you spent too much time thinking; if your opponent had spent as much time thinking as you did, maybe they would have played better and you wouldn't have a winning position.
Time management is part of chess skill. Strong players know which positions need extra thinking time and which positions they can move quickly.
However, there is a version of chess in which time management is explicitly not part of the game: correspondence chess, also called daily chess. If you want to play without any risk of getting flagged, play that. Then you can spend five hours or more to try to come up with the best move if you want.
BTW, @flagger didn't get banned. He closed his own account in v2. People who close their own account in v2 just get the "account closed" symbol, which rather confusingly looks like the fair play symbol.

Time management is part of chess skill.
Put it this way: if there is no clock, if you spend an hour on every move, you should almost always beat someone who is just as good as you if they only spend five seconds on each move. You're spending a lot of time thinking about the position to find the best moves. But that wouldn't mean you were better than the other person, or that you had more chess skill. It would only mean you were taking more time.
If you get flagged in a winning position, it means you spent too much time finding good moves instead of saving some time for later in the game. You have a winning position because you spent too much time thinking; if your opponent had spent as much time thinking as you did, maybe they would have played better and you wouldn't have a winning position.
Time management is part of chess skill. Strong players know which positions need extra thinking time and which positions they can move quickly.
However, there is a version of chess in which time management is explicitly not part of the game: correspondence chess, also called daily chess. If you want to play without any risk of getting flagged, play that. Then you can spend five hours or more to try to come up with the best move if you want.
BTW, @flagger didn't get banned. He closed his own account in v2. People who close their own account in v2 just get the "account closed" symbol, which rather confusingly looks like the fair play symbol.
This
Flagging is a skill. The op obviously doesn't have the skill to flag, or he wouldn't be griping.