The Spitzenkandidat system was never going to work out as intended whenever serious coalition building was involved. It would have been more undemocratic to impose Weber when he has the backing of less than a quarter of the parliament. Parliamentary systems in any country involve negotiations between parties when no one has an absolute majority (except in Canada, because Canada is weird and f**ked up).
That doesn't mean it's worthless. It's still good to have a general "first offer" to see where a party stands. And sometime one of them might actually be selected if they're accepted to the coalition partners. That is, again, how normal parliamentary systems work.
What the hell, I tend to be a pretty informed voter and I heard nothing about this process in Portugal, only the programs and stakes for the national parties. The EU has a real problem with communications, it won't be seen as trying to be more democratic in plenty of countries continuing like this.