That meme is not without some basis in reality, as media people tend to be highly educated fellows who are less impressed by the traditionalist elements of conservative rhetoric.
As people with higher income are more likely to vote for rightwing parties, I guess, this is as well true for more educated people.

So there are a lot of things.

• opinion parts of journalists are often not about policies, but about how well or not well a party follows its boss. Fawning MPs/PMs towards their boss = good, critical voices and lively discussion = bad \ in the last years the SPD was quite a bit wilder than the CDU. Schroeder in the end had as well problems to keep his people together, why else would he had given up?
  
• Everything what "Die Linke" says is bad, toxic. If something isn't introduced by a widely respected person, who hasn't done such a 'betrayal' as Lafontaine (is stepping down was seen very bad from the beginning, not only when he joined Die Linke), it can't be taken serious. If later others follow such ideas, they are called populist (see the heat the CSU got for asking for inflation adjustment of the income tax, this was similar to a Linke proposal earlier).
  
• the journalists have to take into account, what people think. This is quite simple. If the economy runs well, the current politicians are seen in a good light. If the economy runs bad, they are seen in a bad light. This is no different than in other countries. Merkel had simply the incredible luck, that her chancellorship started just at the beginning of an unexpectedly very good year. When the economy slows for a longer time, such as in 2001 - 2005, she won't be seen favourable any more.
  
• journalists are rarely economists. One idea, which was sold to them by both, the CDU and the Schroederites is, that the budget should be balanced. This specific issue gets much more credit than it should get. And the current grand coalition simply was very successful in doing that.
  
• the sense that journalistic ethics requires neutrality leads to views, which are necessarily close to the center. So yes, journalists are at the right edge of the SPD. And when people like Schroeder, Steinmeier, Clement, Muntefering sell something like the agenda 2010, and they say TINA, then the journalists will write TINA, because most of the serious people say TINA.
  
• the grand coalition makes economic policies left of Schroeder. Schroeder: record reduction of the top income tax rate/ GC: 3% increase of that rate// Schroeder: agenda 2010 // GC: prolonging jobless pay  for elderly, the change of stock earning taxation (which will bring in more money over time); this are just small steps, but the direction is obviously in the other direction. So why should a journalist who has believed Schroeder, now attack Merkel, when he is favouring left policies?
  
• Kohl was not at all popular in the media. He managed even to get into a long dispute with the BILD, (while Schroeder said, he can gouvern with BILD and GLotze(TV))