Sir Menzies Campbell says the Lib Dems have "too many alternative power sources" for the era of 24-hour news.
Sir Menzies resigned as Lib Dem leader in October
Sir Menzies, who resigned as leader last year, told the BBC "there are always mutterings about leadership".
But he said "too much vocal public expression" could "feed preconceptions" - in his case cliches about his age.
He had tried to "professionalise" the party to make it "more up-to-date" and "more fit for 24-hour-a-day news which at the moment it isn't", he said.
Sir Menzies said that whenever he had felt that the party under his leadership was making ground there would be some more "unattributed" quotations.
He told BBC One's Andrew Marr Show: "There are too many alternative power sources in our party.
"One of the things I learned very early on is that the leader of the party - the opposite of the harlot - has the responsibility but not the power."
Sir Menzies, who said he had voted for Nick Clegg to be his successor, said that he had been irritated by the "cliche ridden" media coverage of him.
US presidential race
"If I had a fiver for every time someone gave me a zimmer (in a newspaper cartoon) then I'd be a very rich man indeed," he said.
He recounted another occasion when "a female journalist, herself not unknown to the headlines, came all the way to Cheltenham during the leadership election to ask me how I kept my socks up. I mean this dealing in trivia related to some kind of perception about my age".
Sir Menzies, 67, said that, as John McCain was showing in the US presidential race, age should not be the issue - capacity and ability is the issue.
He said that his aim as leader was to restore the party's morale, sense of purpose and get it fit for the next election.
His decision to resign came in the wake of Gordon Brown's decision not to hold an election last autumn.
He said: "We had 10 or 12 days of articles which all raised this question of age... and I asked myself can I trade out of this?
"And I asked some of the most senior people who have been my supporters and advisers can I trade out of this? And they said 'Yes it's possible but you may not be able to do so'.
"And I thought that it was in my, my responsibility, to make sure that I gave the party the best possible chance at the next general election; and the best way for that, was for me to go in my own time and on my own terms."
Sir Menzies, who said he intended to stand as an MP again at the next election, said the country was "in need of liberal democracy" given what he called the current "authoritarian" government.