First of all, there are a very few posters on this thread who claim that memorising TTs is pointless/only necessary if you want to do something maths-y later. The vast majority here, I believe, agrees that 'knowing' your TTs makes a huge (positive) difference. Some very able people may get around memorising them without too much of a detrimental effect, but for the majority it is pretty much essential.
For some people, memorising them is easy, for others very very hard, but nevertheless, if at all achievable, it is worthwhile.
So what are we actually arguing about?
One dimension seems to be 'what is more important, understanding multiplication or memorising TTs?'
It seems to me that this is a pretty hypothetical question, as very few people/children will have a (permanent + complete) lack of understanding multiplication but yet be able to memorise TTs, and equally there will be very few people/children (completely and permanently) unable to memorise TTs (not even 10x) and yet able to understand multiplication.
A second dimension seems to be, what should come first?
Personally, I am not sure this really matters, as long as both are achieved at the end. I tend to believe that for most children, the two develop alongside each other. At times the understanding will aid the memorisation, at times the recall will aid the understanding. Some children will do more memorisation first, other children will achieve more understanding first. Does it really matter, as long as they achieve the end goal of understanding & memorisation? And are not completely put off maths in the process?
I don't think anyone on this thread is advocating that ALL children should (must be made to, if they like it or not) memorise TTs before they understand multiplication at all.
Nor do I think that anyone is advocating that all children must reach a certain level of understanding multiplication (what level exactly?) before they are 'allowed' to memorise.
So what are we arguing about?