I'm not an especially pious person, but I respect the trait in others. What makes me cross-eyed, however, is when some fraud puts on a pious show. Take davening for example.
Now, I understand that some people are bored by prayer. I am, too. (sometimes) That's fine. However, when a non-pious-fraud becomes bored in shul, he goes for a walk, or whispers to his neighbor, or indulges in a day-dream. In other words, he doesn't try to conceal his boredom. What does his friend the fraud do? He takes out a sefer and starts to learn. Message: Look at me. Message: I'm better than you. Message: Davening is for saps. If you fools had any sense you'd take out a gemarah and skip it, like me. (For the record: I don't recall ever seeing a Rav do this. During davening, a Rav davens.)
Something similar, invariably, happens during the Nine Days. The widespread, entrenched, and historically significant Jewish tradition is go without meat and wine between Rosh Chodesh and Tisha B'av. For spoiled children and fish-haters this is a little difficult, perhaps, but most of us muscle through. Pious frauds, on the other hand, have an out: The Rama rules the meat and wine are allowed when you are making a siyam (celebrating the completion of a Talmudic tractate) As a result, such celebrations have been made every day this week, in every Jewish neighborhood.
The problem is that the Mishna Brurah puts strict limits on the practice, ruling that (1) you can't time a siyum special for the nine days; it has to work out that way with nothing artifical about it. (2) you can't make a larger celebration than you might have otherwise, and (3) you can't invite people that you wouldn't have invited otherwise, and (4) you can't attend if you wouldn't have attended otherwise.
Though I'm sure that some siyums legitimately meet the MB's restrictions, most don't. Most (like learning during davening) are just a way for the pious fraud to escape something unpleasant without bruising his self-image.