AST (and DRG) had their improvements pushed to 7.0 PLD are getting theirs in 6.3

[Rilifane]

Ruin II used to be the same potency as Broil, but had double the MP cost. This made it effective for weaving purposes, but not ideal for spamming and was a healthy way for SCH to address mobility. You felt mobile, but there was a soft limit to your ability to do so. It was also a unique way to address mobility and weaving rather than just making Broil have a 1.5 second cast time that had a bit more flavor and feel to it, even if fairly small. I can't really fathom not wanting that over the current Ruin II feeling more inconsequential than it's ever felt before and still taking a DPS tax.

I think MP limiting comfort tools is a much better solution in general. It gives you a softcap and you can decide for your own how to use it and good players will always try to avoid so they can go for higher dps sets with risky MP economy. Aoe GCD heals, mobility and weaving tools can be spammable in theory but with high MP cost tacked on so that you'll definitely feel it if you rely too much on comfort tools instead of utilizing your whole toolkit and playing more efficiently.
It won't punish you the first time you use. Nor the second. But if you keep using them too liberally, you'll pay for it and it sends a message without making it impossible to deal with unforseen circumstances.