I am going with a contrarian viewpoint here. I just think they were extremely unlucky to not win today. They created some chances that should really have been buried. Son's finishing let him down today although he hit the woodwork and was unlucky not to score.
Jose is a pragmatic defense first manager and it is clear that he doesn't coach his teams to take risks when they are ahead but today isn't one of those days where he shut up shop. I do enjoy the schadenfreude though.
Here's the thing: You are right. Not about them being unlucky - it was crap finishing - but about them potentially being able to score more. However this ignores the fact that it has happened multiple times. Jose and the spurs fans can moan about Son and Kane missing chances till the cows come home but the fact is that no one scores every chance they get. In fact the outlier is when Spurs beat us 1-6. In most games you see a miss or two.
The fact that this keeps happening to Jose suggests that it is a problem that's down to him not just the players.
"if Lukaku scored that at Anfield..."
"If Sonny scored that at Anfield..."
"If Guatia didn't turn into Rinat Dasaev.."
"If Lanzini hadn't hit that..."
"If Kane scored that 5 yard header last night.."
It doesn't work like that anymore. Spurs don't have 11 world class stars like Chelsea in 2005 and other teams now have a player or two who can hurt you.
I already see the Spurs who acted like Billy Big Bollocks a month ago claiming they never expected anything this year. This is classic Jose. He convinces you to lower expectations and claims minor wins as great victories. The latter day Mourinho, if he was a military general, would capture a fort and spin it as bigger than winning the battle of Iwo Jima.
Look at the attacking talent they have - Bergwijn, Lo Celso, Lamela, Alli, Vinicius, and Moura. Sure it's not exactly Duff, Schrrule and Oscar but they are more than capable of bringing in an extra 3-9 points a season. Yet the team is set up to ensure these guys provide zero goal threat between them.
He moans that the defenders aren't good enough and it's repeated by his mynahs in the media:
...and yet they have conceded the second fewest goals in the league (16) behind City (12) and ahead of United (24) and the two Liverpool clubs and Leicester (21). If Davinson is so bad just play Rodon. What do you stand to lose? The truth is that Spurs have a perfectly good team to challenge for the title. You can't plead poverty when you have £42M on Sanchez, £55M on Ndombele, £27 on Lo Celso and Bergwijn and a sweet deal on Reguillon. If they had won 2 of the games they drew (West Ham and Wolves) they'd be top.