Asda has been in Hyde for years and has not contributed to its decline. In fact a lot of people park at Asda and then walk into Hyde to do some shopping.
The decline of Hyde has been aided by the council deciding to charge for parking all the time. When the upper levels of the multistory car park were free, the car park was full all the time. - now it is empty. If you talk to the indoor market traders this change in policy has really affected their businesses.