It's a good 'plan', we get the point - but it isn't full proof. There are plenty of newly qualified accountants out their from red brick unis without jobs too at the moment I can assure you. I know one with an ATPL and he has nothing to show from either. When you guys and girls all did things, just like with the flying, they were different.
If you want to be a pilot, be a pilot . If you want to be a pilot and run something on the side because there is only one way salaries are going in this industry then by all means do get a diverse trade to bolster it. Do not do it for a 'back up' plan though. There is nothing back up about it for the period you would be looking for a flying job. The cost of the degree negates any piddling pay difference and most companies will see that you have flying on your C.V. and ask you what your long term plan is before they invest time and money in you. So if you don't mind doing the accounting for a fair few years before starting the flying, then go for it. But knowing how people fall for flying and want to do it NOW, that will take some focus.
It is a change to see someone have some foresight on here, so good for you but really think about what you want out of life and do things for the RIGHT reasons.
Good Luck.