All perfect praise be to Allah, The Lord of the worlds. I testify that there is none worthy of worship except Allah and that Muhammad is His slave and Messenger.
What you mentioned about not going to the mosque for that reason is due to the lures of the devil. You should know – may Allah guide you – that, according to the most preponderant view of the scholars, the prayer in congregation is obligatory. Therefore, you should not abandon going to the mosque for the congregational prayers, especially due to the weak reasons that you mentioned.
The fact that the congregation of the mosque makes some mistakes does not justify you deserting them or abandoning what Allah enjoined upon you regarding witnessing the congregational prayer.
We fear that you are prejudiced against this group and that you exaggerate in despising them; otherwise, it is obligatory to refer to the scholars and abide by their rulings about problematic matters. Then if it becomes clear to you that they are wrong about a certain issue, then you should advise them in a gentle manner and clarify their mistakes to them with wisdom and good admonition. If they take heed, then all praise be to Allah; otherwise, you have done your duty and are acquitted from sin.
As regards your bad temper, then you must struggle to defeat it by adhering to leniency, gentleness, forbearance, and tolerance.
For more benefit on the obligation of attending congregational prayers, please refer to fatwa 82264 and to fatwas 87749 and 85666 on the Tableeghi Jamaa’ah.
Also, for more benefit about controlling anger, please refer to fatwas 91040 and 86681.
Allah knows best.