Good post @Gash
What I wills say I know 1 or 2 lads playing professionally who see Celtic as a great step up with the added perk of the Champions League. Very occasionally players like Nakumaura, Moravcik or Larrson or Kenny Miller for Rangers turn down huge money elsewhere at least until they are over 30 (Larsson) take the club to their hearts.
Its like Olympiakos/Panathanikos or Steua Bucharest have big histories with regular CL Football and crazy fans who travel far and wide but the league is wrapped up between 2 clubs, still doesn't deter from playing/supporting either club.
The SFA really need to help the national team and fans by kicking some life and money and sponsorship into the SPFL and Scottish Football - safe standing and revamps will be a start of that.
The problem for young players is that like Man City many young Scottish player has gone to the Old Firm only to disappear without trace. Scott Allan being the latest player to see his career stall, voted player of the season one year, 18 months later sent on loan to Rotherham. And there's been many other examples over the years. All this does is stall a players career and also hampers the national team as decent players who could progress are seeing their career stopped in it's tracks. Armstrong and MacKay-Steven are similar, they're getting some games but they'd both be a shoe in every week if the were still at Dundee Utd, and both should have 15-20+ caps by now as well. Champions League isn't a perk either considering they either don't get a game or don't qualify half the time anyway.
With regards to Nakamura, Moravcik, Larsson and Kenny Miller etc other than Larsson none of them were every going to play at a much higher level, baring in mind Celtic were still playing at reasonable level in those days, if it was now they be gone in a flash. Kenny Miller had a go at the Premier League a couple of times with Wolves and Derby and largely died on his arse, that's why he ended up hanging around Scottish football for so long.
It'll take a lot more than money, sponsorship (not that any sponsor is going to through game changing money at Scottish football) and some safe standing areas to change things.