Mo himself said "Its not about money" so if its not money what is it ??!!
I imagine if you're someone like Mo or Sadio, and you're getting on in years in footballing terms, you don't want to keep working your balls off all season long only to end up seeing the likes of the sportswashers pipping you to the league after splashing another £100m+ in the latest transfer window. It's bothering fans to be having these outcomes, imagine being a player, they'll feel the same way as well no doubt. So do they want to work and maybe fail in achieving their targets, or do they want to go somewhere else where they maybe don't have to work quite so hard and may have more chance of ending the season winning things like the Bundesliga or La Liga, or, who knows, maybe even joining the sportswashing entities themselves for 'guaranteed' winning.
Look around at the world of football and the amount of players that just want to be part of a winning set-up, regardless if they play much of a role in it themselves. There are many that just want to be winning.
I think the cup wins could potentially have added some doubts about leaving, and I'm sure if we won in Paris they'd both be signing whatever was offered to them, but with missing out on the biggest prizes I think it has their heads turned to the possibility of an easier time elsewhere. If this is the case then we'd be better off for them moving on, as good as they both are, because we need people willing to leave absolutely everything out there on the pitch and to have the belief to win to enable Jurgen's philosophy to be realised.
But as others have stated, it needs to be sorted out one way or the other as soon as possible because the worst outcome is them playing half-heartedly until their contracts run out and then off they potter after a year packed full of the media circus that destabilises the whole club.