The sole problem is that the Grand National has been turned into a handicap chase, indistinguishable from other long distance races. We need to get back to 4 miles, 4 furlongs and a few yards and fences should be harder. The Grand National was all about finding relatively slow horses who could jump fences and stayed forever. It was possible that moderate horses could win a massive payout. This was empathised when the extremely slow Foinavon won the Grand National.
Of course, get the Grand National back and you will get the RSPCA and others on their high horse. But they should be ignored; it is only one race per year.