A league with lots of spectators, young players and money is a base for a strong league. You are saying that the Bundesliga is inferior to Serie A and I am trying to prove to you otherwise.
I agree that it is a strong base, it just makes me wonder why a country like Germany with the economy it has, has taken so long to get to get a national league back to even this level.
It all comes down to what money there is in the league, there is a direct correlation between money and success in football, you only have to look at football from the mid 80's until now to see it. It doesn't matter whether Serie A teams can get it from selling €5 tickets and having 70,000 fans in the ground or by generating the same amount of money through tv deals, because the league is so saturated with coverage. Having 70,000 fans in the stadium doesn't make it a strong league, the money that they spend on tickets, merchandise and amenities does.
The Bundesliga simply has more money coming into the league, the fans, strong teams with wealthy backers and now 'new money' teams like Wolfsburg and Hoffenheim coming in and increasing competition, it pushes the standard of the league up. Add the complete disregard of the UEFA Cup/Europa League by Serie A clubs since it turned into a second rate competition, and that is why the Bundesliga has closed the gap, and looks to have a brighter future, at least in the short term.
Serie A clubs face several problems, mostly because clubs just don't have enough money, don't own their grounds and councils do next to nothing to improve them. The ultras are also a problem in getting families into grounds, and they are the ones who spend the most money. There is no magical fix for it, maybe Serie A clubs aside from the biggest ones will have to have a few quiet years where they channel money into the right areas, and look at domestic youth as well as foreign. The Lega Calcio's short fix is to make a 'Premier League' version of Serie A, give the clubs more tv money, expand the commercial side of the game.
To be honest I don't think it is possible for Serie A to copy the German model, there are just too many differences. Maybe English football could copy it, but Italian football has always been about short terms answers and immediate fixes, Juventus are one of the few who have a longer term plan so it is no surprise to see that we will be the first to own our own stadium. Others will follow, but it might take years.