the thing about SC's i liked the most was that it built cooperation in the party. while effective i feel just spamming WS's makes a non-cannon party look more like a group of individuals as apposed to a single unit. Back when i could make a party at the drop of a dime i had a chain ready for the group and we worked like a military unit almost once we got going. exp flowed like water and mobs dropped like flies. thats the feeling i miss the most.
It didn't really build up any cooperation within the party. In 90% of pickup parties, doing skill chains meant me spamming my TP once I was over 100% waiting to hear from my idiot partner who couldn't figure out to let me know when he was ready to go, even after explaining to them several times. Then, we'd have to sit and wait on the blm to be ready; by which time I was usually close to 200% and the mob was close to dead. Sometimes we'd go ahead with the skillchain which would make the magic burst pretty irrelevant given it'd only remove the last 5-10% of the mob's hp; or we'd wait until the next fight, possibly losing our chain in the process, and kill that mob insanely fast and then have to start the whole process over again. If you're in a static, you've already got the teamwork down so doing a skill chain really doesn't improve it at all.
With TP burns, you don't have two other people limiting your performance and holding back the effectiveness of the party. I'm better geared than most of the other DD's I'm up against because I try my damnedest to be as good as I can be and without having to wait on other people to skill chain I can actually take advantage of that gear; which results in faster kills and therefore more exp/hour for everyone. You let people perform at their potential, rather than hold back the exceptional jobs/players so that everyone can get their job done at the same time. Rather than bring everyone down to the level of the weakest link, you let each perform at it's best; it's a far more effective means to get exp, which is why standard skill chain parties are so rare nowadays.
In merit cannons, everyone's on the same page, everyone's working together, without any instructions or constant monitoring. That's actually
better teamwork than your traditional skill chain party; we're working together seamlessly without even needing to talk about it.
This is of course not counting soboro samurai's, who make skill chain spam out of TP spam. I was doing distortion with 2 war/nin's and a nin, with only a very small slow down in their WS usage; and I barely touched meditate in the process.
Edit: as a guide to how more efficient non-skill chain parties are: when skill chains were king, 3k an hour was standard for a party, 4k an hour was a really good party, 5k an hour was an awesome party. Before ToAU was even released, with WS spamming parties, those numbers all went up 1k each; so 4k for average, 5k for good, 6-7k for awesome. With ToAU, those numbers jumped up another 1-2k each, so 5-6k for normal, 7k for good, 8-10k for awesome. This is of course with a non-cannon style setup, otherwise you would have an even bigger jump. Skill chains are just an inefficient means to exp, it just took everyone a while to realize it.