The plan B is to send it again when they’re back though. I think there are a lot of situations where I emailed them and someone else from the start and someone else answered, or I found someone else in the 2 months span until they’re back, or did it myself, or it’s too late to help…. So it does help them avoid following up on things that don’t need following up on.
I wouldn’t be offended or consider saying anything to anyone who included this in their out of office message, but even as someone who is in a religion that forbids use of electronics on most holidays, I still think this message is 1) TMI; 2) doesn’t convey what it needs to convey unless you are explaining that you don’t use electronics during holidays, in which case you can just include that you won’t be checking email without including the religious explanation; 3) would come across to me as inclusion of personal information I don’t need, which would therefore strike an unprofessional tone,and I wouldn’t understand why you felt the need to include that info. How about “I’m out of the office without access to internet or email until (date). If you need assistance before this date, please contact…” Like I said, I think your colleagues are overreacting, but in general I would advise to leave all personal information out of your auto-reply — vacation, medical leave, religious observance, etc. — people do not need to know why you are out.

I no longer work at this company due to the misalignment with advertised company values and actual practice.
When one of my colleagues went on vacation, he sent an out-of-office message that was both clever and smart. First, he sent the recipient on an imaginary scavenger hunt to "the highest peak of the tallest mountain." He used humorous absurdity to make it clear that he would not be checking email while he was away.