I had a "dummy" until I met DH at 18yo. I sucked my thumb up until then, every night and during the day when I got stressed. He was the first person who made me feel safe and secure, ever. I have never sucked my thumb since, other than when I was in hospital and felt that I was not in control of what was happening.
Give them a break. They are allowing their child to feel secure, which with papzs all over the place must be hard enough as it is, without getting pressure from judgemental, misogynistic newspaper editors getting their oar in.