I don't think anyone in here even came close to suggesting that, I know I certainly didn't.
Part of Aura Steal is a drastically increased success of Steal landing on buffs. Even with a single merit, Aura Steal is a close to 95% dispel. All additional merits do is increase your chance of actually receiving the buff you stole instead of just dispelling. The only problem with Aura Steal isn't that it's an addition to Steal or even the choices of Buffs we can steal, it's the fact it's stuck on a 5 minute timer. That leaves the utility of the ability incredibly low. Just lowering Steal's recast to 1 minute will fix Aura Steal so that it's actually useful...even if it's mainly for the Dispel.
To be perfectly blunt, as someone who's been playing Thf for over 8 years, I can honestly say that Steal and Mug have never been useful in this game. Nor has Despoil despite being added fairly recently. Of all the "Stealing" abilities, only Aura Steal has actually had any use in any kind of fight, however that use is almost worthless due to it's absurdly long recast. All that said, in this day and age, Steal and Mug have only become more useless since most mobs have neither items nor cash worth taking.
All that said, while the actual ideas to fix these problems seem to vary, we all (save for SE) seem to agree on one thing. None of these abilities are useful and all of them need to be fixed.