I think part of it is reading the scare stories on forums like this. "Your child will be exhausted and anyone under 10 needs a stroller," "no more than two adults can fit in a budget level hotel," "you must have ADRs to have a decent vacation because the table service restaurants are awful." etc.
Everyone wants to have the best vacation ever, so the scare stories seem believable. People need to understand that these things are opinions, not facts!
That's why people like me continually feel the need to add the opinions that "no need for healthy older kids to have a stroller," "we fit two adults and two adult sized teens in POP with no issues," and "we ate counter service and had a good variety." You really have to hear both sides to get a realistic picture - not just the scare stories.