Why do players feel that they "haven't won" when they accomplish a swindle?

I from time to time see players say that they don't feel good about a win because "the other person blundered." I don't resign games ever as I always feel like making every piece work as hard as possible. This has given me a reasonable share of Marshall-esque swindles. Was I outplayed all game save for a few moves? Definitely. But the object of the game isn't to play great for 30 moves, it's to checkmate the king. I often hear "good players don't make blunders in the endgame" etc. etc. but my own experience (at least against 1700+ players on this site) is that there is a much better than 1% chance of committing a swindle for a win or draw against players ranked anywhere in the 66 percentile (about 1750) rating and below on this site.

Here's my most recent swindle-my opponent is a better player than me as indicated by his rating. Yet despite being a rook down in the endgame I decided to plan an attack. I knew that it would be unlikely to work, but felt compelled to try.

The attack begins with my 30. H5. I could sense that my opponent wanted the security of a second queen and would ignore my pawn if I could get to H3. This is particularly so since his queen sits on D5, protecting G2. 33. C6 is to give me breathing room (and to distract from) my crucial move of 34. E4. Now I have a two-move mate if my opponent neglects to keep me in check. My intuition was right that he did want the second queen, a bitter Pyrrhic consolation for my opponent.

en.lichess.org/oQLQhIFZDOBP

Here's one from a month ago that I really enjoyed. I'm down a pawn and a minor piece in the endgame. I just decide that I'm going to try to get a bank-rank mate and starting at move 33, I fight for every inch of the board. Because the kings are asymmetric, I think there's a chance my opponent doesn't see what I see.

en.lichess.org/19t3Uaoi#88

These examples aren't to brag but to question why so many of my opponents simply resign and move on when there are some tactics left on the board.

A final note-32 of my classical games ended in stalemate. 25 of those involved me accomplishing the stalemate. I'd be ranked about 1500 if I resigned all my "lost" positions. Food for thought.

tell me why I can't write in chat?...I have a button to send messages there? where's it gone? can you help?

Chess is a great game because of games like this one....
Opponents get very angry when this happens!

One more:
en.lichess.org/EW2ez9GIo3yP

Love it Tangelo. I notice that a good amount of players in the top half on this site still have trouble with actually achieving a checkmate, even with significant material imbalances. I still usually end up losing but time pressure and aggravation often lead to blunders and potential for stalemates/draws. I have a theory that a lot of players are so used to getting resignations that they aren't as good as their rating past the point of resigning (i.e. playing with an advantage). So a 1700 player plays like a 1700 up until getting a +3 or more advantage, but plays more like a 1400 rated player with the lead. Obviously not everyone, but I think there is some truth to it.

I mean, if winning is all that matters, then it's all fine. I just think some people care about playing their best game, one they can actually be proud of. I think as you get better you'll probably encounter less blunders in won positions

Furthermore I think holding out to see if your opponent makes a mistake can be a bit disrespectful.

Fair points beardedrainbow. I absolutely expect fewer blunders in won positions as I improve though certainly not zero mistakes (at least by human players).

I suppose that to my mind I don't view a blunder as necessarily an event that only one player contributes to. Pressure through tactics, diversion etc have lead me to commit blunders, and I'd give some credit to my opponent for having exploited that.

I don't agree with the disrespectful comment though admittedly a lot of people feel that way. The fact that so many players ranked at the 65th percentile and lower on the site have issues with actually accomplishing a checkmate, I almost feel I do them a service by forcing them to think through a finish, or re-visit their training in endgame/mate scenarios. I can see that not being as applicable the higher you get, though I tend to doubt I'd resign games even at a much higher level.