I'll put this from the perspective of a Blues fan who can afford to drop money on tickets if I choose, when I choose.
The next chance I'd have to go to a Blues game in St. Louis would be December 29 vs. Winnipeg. For two (2) tickets to that game, the cheapest seats currently available through the Blues website are $90 each to sit in section 330 (end where the Blues defend twice), row J. To sit on the end where the Blues attack twice, it would be $98 per to sit in section 314, row G. For four (4) tickets, it's $110 at the cheapest for section 327, row M; to sit on the end where the Blues attack twice, it would be $125 per for section 306, row M.
To sit up high, circa the blue lines or goal lines (where I prefer to watch), it's only more expensive.
And remember, that's a price per ticket, excluding fees. (Not checking to see what fees are from Ticketmaster, I just presume it's two pints of blood + your firstborn + your firstborn's firstborn and am surprised if it's less, but let's say 10% of the stated price - which might well be low.) So, if I'm taking a kid we're talking easily $200 plus parking (say we take Metro to the game at $5 round trip), plus whatever concessions and merchandise we get. If I'm wanting to take the wife and kids that are at home, we're easily at $550 or more.
$550+ for a one-night event + hassle of the crowd, getting in/out of bathrooms, dealing with traffic, and getting home around midnight or so? Or, $449 for a 75" HDTV where we can sit comfortably at home, do what we want for dinner, pause action to hit bathrooms if we need, and so on? It's a no-brainer. Hell, even last year I got 4 tickets to Tampa Bay while the team was still in the dumps before it caught fire, and that was still nearly $400 to sit in section 310, 3rd row from the top; it was neat, but that was also a birthday present for someone. I wouldn't do that even semi-regularly at that cost; I'd rather have spent the money watching at home.
[For the next non-weekend game, it would be January 11 vs. the Rangers; 2 tickets are $76 per, 4 tickets are $93 per - both excluding fees. And, since it's a weeknight game, there's school and work the next morning and all that and you're still not getting home until about midnight.]
Don't get me wrong, I love to go watch games in-person, but for the current cost/value I'm not going to games unless there's a really, really compelling reason to do so.