I asked you "to what end" because it got us 7th this year and presumably another 20 goals this season would only get us similar. And it's exactly because of the reasons you state, we have holes elsewhere in the team. So my calculus is why keep a player when the big money can help us round out the squad? Keeping him only kicks the can down the road to next summer and all we have to look forward to is another 7th place this season, an unhappy star player, and less money to put toward the rebuild.
You make a fair point, use the Kane money to fix the holes in the team. And I'm not against selling a player who wants to go. But I am very against a club with near enough endless amounts of money dictating the price for Kane, which is really the crux of my disagreement (gentle disagreement, mind) with some posters here, your good self included (I think I read you would take an offer of £100m).
I'm repeating myself but I really think as a club, we need to draw a line and say that if you want our best player with 3 years on his deal, you will have to pay over the odds to get him. If they are willing to pay £100m for Grealish, they can pay £150m for Kane in my opinion.
And if we don't get that kind of offer, we keep Kane. And for reasons previously stated, I think Kane would continue to play as he always has and be a consistent, productive player. Sulking and bad body language isn't something I care about, it's never done Ronaldo's teams any harm - he sticks the ball in the net, the others do their job, games get won and people are happier all of a sudden.
And Ronaldo is probably the best example of a player who plays for himself and his legacy most of all, but his teams do brilliantly because they utilise his greatness (goalscoring) and his team-mates do their jobs. Kane is in this mould I think. Not as great as Ronaldo, obviously. But he does care about his individual records and achievements, I believe it's part of what drives him as a player. He's not going to down tools when he is chasing Shearer's record and the World Cup is on the horizon.
It's not unthinkable that we sign a couple of defenders and Skipp has a breakout season in midfield, Kane and Son bang in the goals and we end up with Champions League football. We'd still be able to get £100m for Kane with 2 years left on his deal, and rebuild from a stronger position than where we are right now. That's my thinking, if City aren't willing to pay up.