We were pretty strong from the mid 60s through to the mid 80s tbh. The 70s really was a wasted “golden generation” though.
We lacked tournament savvy back then, and we still lack it today.
There was a documentary on a couple of years ago about fans selling houses and businesses to go to Argentina to watch Scotland, some people took weeks to get there using all manner of routes and transport methods, it was a lot harder back then as International travel routes weren't as widespread but fair play to the ingenuity of those who made it

Anyway part of the program talked about the team / squad and tactics, there were players who said at the point of running onto the pitch they didn't have a clue about the opposition or the players they were up against.
Even back then it was normal to compile some sort of information dossier on opposing teams and their star players but apparently Ally did the square root of Fuck All

Edit - Just found this article which summarises it so much better than I can
External Link/Members OnlyNo research was done on the opposition. A television company offered MacLeod an all expenses paid trip to watch Peru before the tournament, but he turned it down. In qualifying, the Peruvians had topped their section ahead of Chile and had put five goals past Bolivia, who had already knocked out Uruguay, but Scotland's players knew none of this. Peru played Brazil and lost just 1-0.
Iran were a poor side but no work was done on how to expose them. That was the ultimate sin. MacLeod was in too much of a rush to get to the final to worry that much about how he intended to get there.
I was only a kid back in 78 and the prospect of being able to watch the WC on TV was Manna from heaven despite England not being in it, or as was constantly pushed down our throats from the Scotland squad song "We Did'nae Qualify"

In my desperation to get involved I duly put up a WC wall chart using blue tack as my Dad (Mr Grumpy / Negative personified) told me that I wasn't putting that up with drawing pins as "You'll put holes in the fucking wall and it's me that got to fucking redecorate"
I, indeed like many naïve young English kids rooted for Scotland as it was the closest thing we had to being there ourselves plus most of the players played for the top English clubs at the time so it was like an England team right

Anyway I also remember my Dad informing me "Why are you supporting Scotland, those "Fuckers" wouldn't be cheering for us"

OK so he was right on that front and 48 years on I do regret my misplaced loyalty to Scotland and i've been trying to make amends ever since to the point that I appear to have become my Dad, something that I said would never happen but I guess the apple doesn't fall far from the tree eh