The only thing that needs to change to make 25s better, is the quality and desire of raiders to do 25s. As an officer of a former 25 man guild that is now a 10 man guild, and more importantly the recruitment officer, the biggest challenge facing 25 man raiding is the culture of game and the mentality of the raiders.
I don't care what Blizzard favors or not, but give me 30 or so raiders who will show up, know their class to an expert level, and research fights - and I'll run a 25 man guild.
Well, yes, that's the focus on administrative burden that I'm trying to say needs to be compensated for to make it worth doing. You'll get better quality raiders if they introduce things that increase the desire for high-quality raiders to want to join the raids. People are going to follow the path of least resistance - so either you need just one path, or you need to acknowledge that the two paths aren't equal. You get officers willing to do the work if Blizzard provides multiple layers of support and the raiders have the desire to run the content. It's possible that Blizzard pushed the culture of raiding so far that 25s aren't long-term sustainable into the future of WOW, but they also hold the power to bring the teeter-totter of desirability back towards 25s if they want to. However, all their decisions favor helping 10s at the cost of hurting 25s.
I'm sorry Lissanna, but the entirety of the post you reference is spot on with his analysis, and yours misses some key elements. A 25man raid is run by a 25man guild, and his post suggest that it's not just the raid formation/strat elements that make it rough, but the fact the playerbase leaves much to be desired. By giving incentive to raid 25, you have more 'junk' as a guild leader to sift thru. I have LOTS of ideas to incent guilds to run 25man outside of quality of loot drops. Here's just one, if you're in a 25man raid group (non-LFR), when you enter the instance, your gold charms are increased so you get more personal rolls.
Path of least resistance theory is invalid because it's missing the motive of each person choosing, and we all play/raid for different reasons. The reality of 10s v. 25s is they both kill a boss, that deserves equal reward (which already favors 25s in loot per person). The rest of your post suggests that 25man raiding may be in decline, which it may be. So if you want more 25man raids, establish benefits for 25man GUILDS.
For example, achievements w/guild perks that can only be obtained via being in a 'guild run' 25man (guild meta w/personal level requirement that requires a maintenance feature so ppl don't get the benefit then abandon the raid group). I'm sure the creative juices of Blizzard could come up with some valuable non-loot-quality advantages, but here's a few: Increased valor point cap to 4000, increased charm rate, a return of Have Group, Will Travel, increased gold for dailies, and heck any other benefit we currently already have that will increase convenience and enhance gameplay for retention.