“If people are being less frum than you – ie., doing things you feel are wrong, you have every right to be upset. That’s the way it should be.”
Maskim, but on the other hand if they are not actually doing something wrong, but simply haven’t gotten up to your level yet in some area (for example, they don’t daven with as much kavana as you do, although they are trying), then Sam2 would be right.
And that might be similar to the way in which the “more Frum” people are “more Frum”. In other words, I think that MW13 was referring to a case in which the way he is doing things is fine, but someone else reached a higher level in that area. Alternatively, they simply have a different idea than him about what the ideal behavior is, but neither one is clearly wrong or right, and theirs has the appearance of being “Frummer”.
The opposite of either of these should not bother him.