I'm not sure that's really a "Labour control" problem so much as it is a constitutional one. So long as the most important decisions are made in Westminster, it's always going to be the Premier League to the devolved region's Highland's Amateur C league. If you're a talented and ambitious young Scottish politician, would you rather be vying for a seat in Holyrood or Westminster? This might - might - change if things like tax raising powers and the like were devolved, but even then it's questionable unless your interests are purely domestic. This is a problem that the SNP typically don't have because of their particular interest in Scottish devolution (and Plaid in Wales etc), but for any national party, they're always going to struggle to keep talent locally.
Edit: To reiterate, this isn't a "Scottish issue" - it's the same with every elected position which isn't an MP, with the possible exception of Mayors. A lot of MPs start life as councillors for their party and then stop being councillors as soon as it's politically viable to do so, which leaves you with the various ailing buffoons, retirees and wet-behind-the-ears cabinet ministers of tomorrow. I think the only solution to these problems is to give local areas greater control over the things people care about, but that's localism in a nutshell I guess.