If the invited guests are family or close family friends, it's one thing.
Two very close friends threw a bridal shower for my DIL-to-be, inviting primarily a group of friends who have known one another for years. My DIL had not met them, and my son doesn't keep up with them because they are DH's and my friends, but they have watched him grow up, as I have watched their children grow up. Our friends had heard about DS's and DILTB's meeting, their courtship, and their engagement, and most of these friends traveled to attend the wedding.
I was delighted to attend showers for the sons and future DIL's of these friends.
When I was getting married, I wouldn't have understood how much fun it can be to attend a shower for someone I've watched grow up, and get at least a little acquaintance with the person who is marrying into my friend's family.
On the other hand, getting an invitation for somebody random, whom I don't really know, does feel like a gift grab.