Can't say I feel that way myself right now. I've been paid for readings before, and I didn't feel guilty for it. I provided a service, I was paid for the service. That's how I view it myself. I have offered readings for charity as well, and I see that as being "paid" for what I did, but in a different sort of way than financially. I've heard of others who will exchange a reading for a trinket or something else small as payment rather than taking money.
I know there are others on the forum with similar views to yours. When I was younger, I did have that view myself, and I respect anyone who wishes to do it that way as well. What ever you wish to do with the cards is up to you in the end.