I personally wouldn't worry about it - your new dojos 'blackbelt' standard is simply different to your old dojo... Maybe they're looking for different things. Although, my first teacher used to say that it doesn't matter what grade you call yourself, it only matters that you can get up on the mat and actually do it.
There are people out there who are vastly under-ranked, for whatever reason. There are people who are equally over-ranked. Sometimes those people are from different dojos in the same organization. The number after someone's name is only a guideline, and not a very reliable one at that.
If you think the students at your current dojo don't meet standards, your choices are:
* Get on the teaching staff and work to fix the problem
* Focus on your own training and don't worry about them
IMO, the more important question is whether this dojo is the best environment for your own training. It's hard to improve without peers, and it's hard to improve in an environment that doesn't value the same things you value.