I'm not sure it's entirely a matter of 'where did it all go wrong'. Our main rivals in those days were Sheffield Wednesday & Burnley. Compared to them, we're not doing badly.
If it all started going tits up, I guess it was probably in the nineties, as you alluded to. We just seem to lose our way. The Goons hired Whinger, and we hired the three gems you mentioned above.
Up to the early nineties we were winning trophies still. So, I guess it's telling that we have only one one in the last quarter of a century. Before that, it was rarely more than ten years in between winning something.
I think also that we got a bit caught up in this reputation for only playing attractive football, which came to its zenith with the famous five in the nineties. Great entertainment, but could we score one more than we conceded was the thought before any game. Winning things needs pragmatism as well as adventure. It also requires balance in a side, something the double side had in spades. They strived to play attractive football, but could dig in and grind out a result when called for. And in you wanted to play rough, well Mr Mackay would be only to happy to oblige you! It's something I've rarely seen in any Spurs side since, and my feeling is that until we add that 'bit of backbone' to our way of thinking and playing, very little is going to change.
Very interesting take on the subject and I'm always keen to hear the views of those who have seen more of the Tottenham Tragi-comedy than me!
From my generation's point of view (no offence meant), I guess the defining moment of 'losing our way' was the appallingly ill-advised back to back appointments of Gross and Graham. Those two did more harm to the club in 3 short years than any other manager in the PL era. Graham's style of football was antithetical to the ethos of the club (even that 1999 cup win was one of the most dour games of football I've ever had the pleasure of sitting through), whilst Gross was simply a clown. It is telling that ENIC's first move as new owners was to appoint Hoddle as manager to restore a lot of lost faith amongst the fans, although he was severely undermined by the departures of Ginola and Campbell without being given the funds for adequate replacements (sound familiar?).

<run>
