I think it was down to the fact they didn't evolve their formula for making movies. What was once innovative became cliched but then, most art forms run in cycles. The comment about 'slashers' killing off 'hammers' are relevant imho eg. grunge killed metal but then it resurrected.

Hammer had a pretty good innings. The only genre I can think of that has always remained relevant, probably because to make a good one requires pure skill, is the psychological thriller (strong violence usually featuring). From Psycho to Irreversible to Se7en to Les Yeux Sans Visage to Marathon Man.

I suppose we've seen a smattering of true Gothic horror movies surfacing here and there. I really loved The Wolfman but it was more in the spirit of classic Karloff/Lugosi era horror.

Perhaps that's a question for some of the die hards on here; not so much what killed Hammer but, is it even possible in todays cinema for Hammer to have a resurgence or for another company to replicate their brand and impact?