That's seems the only logic reason for harry kane to stay in Tottenham, if he really love the club and want to stay even without winning titles because he love the club no one can blame him, but many football fans hope to see this player in a bigger club
It looks like Harry Kane would prefer to stay at Spurs for that reason and maybe it's okay for him not to win any titles as long as he's wearing a Spurs shirt. But sometimes if that's the case with other players, of course he has moved to another club a few seasons ago, but not with Harry Kane as if his soul is very much one with Spurs. But whatever decision he makes we have to appreciate it and if he starts to change his mind before the summer closes it will be better for his future to be able to win trophies with other clubs.