I gave my group free expertise at level 5 for any conceivable weapon or implement they might want to use (if there was a way in CB to apply this to racial attack powers and the like, I'd do that too). Players don't like it when they miss, I don't like it when they miss. I prefer an overall higher hit rate, and I can adjust encounter difficulty with that in mind. So for my game, they are neither a feat tax, nor power creep. Just another one of those knobs and dials I can play with. Really if the feat didn't exist, I don't think it would make that much of a difference. I'd just be using more lower level creatures in combat to keep hit rate about where I want it.
But for the average game, where DM is not making such house rules, or is running modules or LFR, Expertise trumps so many of the conditional attack bonus feats, that every character is likely to get it at some point. And a feat everyone has, doesn't help the individuality of a character any. One person with Plate proficiency, another with Toughness, and another with Human Perseverance have all spent a feat for a defensive purpose, but they do it in different ways. Bow expertise, heavy blade expertise, holy symbol expertise, and staff expertise don't really add a new dimension to a character. It merely pigeonholes them into a lack of versatility. A paladin or cleric who wants to use a weapon and a holy symbol is taxed even more. A warlord who uses a heavy blade, but wants to also throw javelins is taking a handicap.
Actually a similar problem exists with magic weapons and implements,a nd characters who like to remain versatile and keep around a melee and a ranged weapon. As DM, rather than going by your typical treasure guides, I try to make sure everyone's attack option slots have a similar bonus at each half-tier or so. I rather wish items did not have +X bonuses, but only had properties. The +X could easily have been built into the system.
I'm drifting off topic here, but back on Expertise, I don't think there is a consensus, since every game is likely to have different dynamics, different degrees of optimization from players, etc. It's just one of those things the DM has to decide whether it will be allowed, disallowed, or free. "Allowed" is probably my least favorite option. I'd rather be disallowed to get it in a game, or get it free.