There is enough room on BBC1 and BBC2 to represent the whole of the UK but the BBC repeat a lot of stuff, meaning that opportunities are lost for regional programming to be shown nationwide. This would improve the BBC's reputation across the regions because viewers would feel they are being given more than just a token mention.
A factor in the dissatisfaction from viewers in Scotland which contributed to the creation of BBC Scotland was STV's failure to commission the types of shows which have ended up on BBC Scotland. If these had been tried out years ago then the apparently untapped potential that justified an entire channel wouldn't have existed and money wouldn't have been wasted.
The BBC have likely found out that the range of content that can appeal to viewers in Scotland is limited, much quicker than they would have had the majority of the programmes they hoped would be successful were exactly that. They are now scrambling to recommission anything with a hint of an audience and constantly look to Still Game to get people to tune in. The situation is all the more worse because they have to repeat programmes that flopped first time round so the channel offers very little most nights.
It's the same stagnant schedule and lack of new content that plagued BBC Three back in the day. Unless this is accounted for, there is no point having something labelled "full of repeats". Even if it was a case of deciding which channel to keep, would BBC Scotland's budget be enough to prevent BBC Three from falling back into old habits?