I think it's not about whether changing lens is good or not. The brother is trying to ask her sister whether she knows enough knowledge to be a proficient photographer or she just wants to bring out lots of gear and end up not knowing what to do.
Those experienced will be "photographers" because they will be taking nice photos.
Those who just BBB for sake of BBB and not learn the skills will end up changing lens all the time in a "lost" manner and missed out the chances to shoot.
Me? I won't say I am experienced enough to be called "photographer" but I guess I am not a lenses-changer.
I do Events Style Photography With Flash most of the time with 18-105 and i always had a Backup 55-200 which i got it years ago
This is exactly why the manufacturers should come out with a 8-300mm f1.2 ef is macro lens asap. :angry:
if a photographer change lens because of need, there's nothing wrong... a more controvertial qns would be... are you a portraitist or xmm shooter? hahaha...