Not reading anything premised on a demonstrable falsity like that first line.
The electoral dynamics in Scotland are very different from those in the rest of the UK, and its 59 seats are often decisive in a general election.
Just… nope.
tl;dr: Between 1945 and 2010, MPs returned from Scotland decided who governed the whole of the UK on three (possibly four) of the 18 elections.
That ain’t even close to “often”.