The particular example I'll use for why we need more interrupts/a shorter cooldown: I was fighting a rare spawn pandaran monk. I was doing just fine at kiting him through the spinning kick and then running back in to avoid getting my butt kicked with the energy bolts. Then he casts healing mist. Okay, I'll interrupt it with solar beam. Back to a bit of melee, then dodging the spinning kick, then - what's this? - another healing mist! Okay, let's try disorienting roar. Yay! Interrupted! But, oh, nope, he goes right back to casting it as soon as the disorientation wears off. He finishes the cast and goes to full health.
This, in combination with boomkin DPS being nothing spectacular, means that I can't possibly solo that rare spawn, where a lock or hunter or probably pretty much anything other than a druid could. I can be as prepared and knowledgeable about the fight as can be, but it's mechanistically impossible for me to do it.
Beyond just the one example, I'm really tired of being one of the knowledgeable ones in the group who knows when to use interrupts, but is forced to rely on other DPS who may not know when to interrupt. Let the prepared players act on it. Especially if I'm going to be pugging dungeons with a bunch of inexperienced players who don't know how to play their class, at least give me somewhat of a better opportunity to help the group survive. Even if it means nerfing the silence effect on solar beam, it would be better than what we currently have.