As much as people like to complain about them, Blackpool would be nothing without classics like Grand National, Flying Machines and Big Dipper (I very much consider Wild Mouse part of this equation too).
The main problem with the park is that their more modern additions have been, for the most part, extremely poor. Rides like Infusion, Steeplechase, Ice Blast and Sky Force are not good. In fact they're the kind of thing somebody would expect from any old tacky seaside amusement park (and we have plenty of those in this country). Icon and Valhalla were the exceptions to this (and of course The Big One has a solid reputation). As much as the park might be aiming to emulate Liseberg, the park just doesn't have the quality attractions of its Swedish counterpart.
So what really makes Blackpool stand out from the likes of Adventure Island, Fantasy Island and Great Yarmouth Pleasure Beach is its abundance of classic, historic attractions. These are rides that generation after generation have enjoyed and they have real heritage value.
The second you remove these rides from Blackpool, even if you replace them with something decent (and historically the odds are not good that they will), you lose one of the main appeals of the park. Furthermore, as I have outlined above, some of the more modern additions are utter dross and should be earmarked for removal a long time before replacing any of the heritage attractions is even considered.