I really hope they decrease the difficulty on T1-4.
That said, I'd either drop a tier or just start wasting tickets. If you're running STR every day people are going to get burned out. Plus, if you start wasting tickets, those zero posters may start participating because they know without participation they'll waste tickets / currency / rewards.
Or maybe you just ask for people to commit to using 1 team a day. Set the bar low so guild mates start engaging with it again. They may find they are having better success and come back to it on their own.
You're right though, it's a tough spot right now. Guilds are having trouble recruiting if they're not running Heroic because a lot of guild hoppers out there feel entitled. So kicking people just reduces tickets and may not be able to replace them with equal quality.