It's mostly just you getting older I reckon. In general the sport's been taken over by the middle classes and been reorientated towards them, with mixed results. I like the improved technique and fitness levels, and the vast improvements in the standard of football journalism. I don't like how someone getting hurt when playing sport is now considered the worst possible thing that can possibly happen ever, and any remote chance of it happening needs to be stamped out completely regardless of the cost to the game. Terraces are a huge loss too, it really hits home when you go to a terraced gaelic or rugby match how much of the experience has been sacrificed for a clearly excessive health+safety measure.
I don't really agree that Premiership ticket prices are too high though. The demand for them is huge, they'd just be bought up and sold at even higher prices by scalps anyway (as they already are). At lower league games that are barely half-full the prices just amount to the club taking advantage of the small core of ultra-loyal fans.
I dunno, there's just something a lot more clinical about watching top flight games these days, which is probably something to do with the amount of money involved, albeit not exclusively. I suppose some of it is to do with me getting older, and rose tinted lenses and all that, but there was something about my last trip to watch Arsenal at the Emirates where I felt distinctly like I was a "customer", rather than a fan.
I daresay it will vest my support in Arsenal as long as I live, it's probably too ingrained to ever shake off even if I wanted to, but there's something about all the big stadia and the money and corporatism that means I don't really feel like part of the club. It's why I never use "us" or "we" when speaking.
The bit about getting hurt that you mentioned, however, is also inexorably linked to the amount of money in the game. Footballers are basically assets rather than employees, or, dare I say it, players these days. The stakeholders with the most influence in these matters are of course the clubs, and they're going to do whatever they can to protect their investments. The insurance fees paid out by clubs on player injuries was huge about ten years ago, so hell knows what the average spend is these days. (I realise you probably weren't actually suggesting otherwise, but I think this sort of thing is inevitable so long as money continues to pour in).