SirChenjin the purpose of these clubs is not to encourage a societal mindset which says that we are old (or in our golden years) at 50.
But you need to remember when many of these clubs were set up many people, men and women, were exhausted and old at 50. Worn down by a lifetime of heavy manual labour in all weathers and low incomes and for most of their lives unable to afford medical care. The introduction of the NHS has probably done more to improve the health of older poor people than almost anything else.
I think there are very few people, if any, in their early older age who are remotely tempted to think themselves old, just because a club for older people takes members from 50.
It is like retirement schemes that take residents from 50. I never met anyone under 70 in one of those developments but they have to allow for the occasional older resident with a much younger partner.
It was a shock and revelation to me when I became a volunteer home visitor with what was known then as Age Concern, how many times I was going out to visit 'old' people, who were actually younger than me (I did the work between my mid 50s and mid-60s.
I think we should talk of the people who attend these clubs with respect. Most members continue to come from the less well off in society and most have still had a life of poorly paid unskilled manual labour, even if not as hard as that of their parents and grandparents. Had you had the lives they had had, you too would be glad of an over 60s club and the chance to meet up once a week for a cup of tea, possibly a singsong, and a day trip to Blackpool.