The facts appear to backfire on your comment.
In the 12 years prior to 2000, the highest average attendance was 28,273, compared to 43,321 for the Dippers.
Once the difficult days became history, ownership changed, Pep arrived and success became more consistent, that average has shot up to 54,219.
Fairweather fans?
Similar to your point regarding Klopp, when the time comes for Pep to depart, it will be interesting to see what happens to the support then.
The teams to admire are the ones who are not so successful, yet every week their fans turn out in large numbers in all weathers to support them.
He said, ‘Liverpool’s highest attendance would not be in City’s top 20.’
Here are City’s top attendances and they aren’t extensive of those above the Liverpool record:
Attendance records of games involving Manchester City Football Club
bluemoon-mcfc.co.uk
Liverpool’s highest
ever attendance is 61,905, there are 18 clubs with higher records than that and many with multiple attendances above that.
We did have higher average attendances than Liverpool when Keegan was in charge:
2003-04 - City 46,235; Liverpool 41,777
2004-05 - City 45,192; Liverpool 42,568
And under Pearce we had two attendances higher than Liverpool’s highest in 2005-06, and six attendances higher than Liverpool’s highest in 2006-07.
We were getting 54,000 before Pep arrived:

(Pep was announced in February 2016 and came in June 2016)
Have a read of this one:
On this day (May 10) in 1947 a solitary goal from Alec Herd against Burnley was enough to give Manchester City promotion. The attendance for this Second Division game was recorded by the media at the time as 67,672 but official records reviewed almost sixty years later showed that City actually...
gjfootballarchive.com
‘For comparison purposes it’s worth looking at the attendances of the Division One champions in 1947 to see how the Blues compared. This attendance against Burnley was almost 17,000 higher than Division One champions Liverpool’s highest crowd that season (52,512 v Wolves in December) and the Merseyside Reds nearest home game to City’s Burnley match was watched by 48,800 and that was Liverpool v Manchester United (May 3). Liverpool did average 45,732 that season, whereas City averaged 39,283 but they were a Second Division club.
The City-Burnley crowd was the Second Division’s record at the time and it was higher than every First Division crowd since the 1937-38 season.’
And you do know that 28,273 average attendance you mentioned was when we were in the third tier in 1998-99 and was a record at that level?
I do agree Liverpool fans are not fair weather supporters though. They have the second highest all-time average attendance, while never having got massive crowds they’ve been one of the most consistent and least fluctuating set of fans for attending.