Some abandoned games occur when a mobile device or a computer battery is depleted. The system doesn't usually appear to allow enough time to reboot a mobile device or a computer after a software crash. Life happens some people have other things that become more important while a game has been initiated.
You can report opponents who are stalling or quitting by clicking the r report icon located on the bottom section of the chess game dialogue box.. Chess.com will take note of the complaint and if enough complaints occur then they will send a community guidelines warning.
If you were playing OTB, would you just get up and walk away, abandoning the game when you blunder, without a "well done" or a "congratulations"? No, you wouldn't. So don't do it on Chess.com.
If you are in a clearly losing position, either play on, or resign in good grace. Chess.com should amend the record of every game that was "abandoned" to read "spat his dummy out like a baby".