I'm coming in quite late to this, but please excuse me, I'm new!
Weaning before a year is quite a modern/western idea, therefore so is puree. But when our friends, parents and even grandparents tell us that's how they did it and the professionals are telling us that's how to do it, what are we to know?
Scientists are trying to put right the fact that in the 1950s formula companies said breastmilk was bad for a baby, by studying the digestive system and weaning. If you do a search you will find next to no (won't say none because I haven't found any, but I haven't looked at every single page) evidence for weaning by puree - other than people like AK who get quite fluffy with the science - iykwim. You will find studies going back many decades on finger foods. As someone said, it's not very commercial to follow breastfeeding or BLW over formula or puree.
As for quantities, Isobel has eaten large amounts from the start. She loved food and always went straight in. Definitely always been more than you would count in spoons! But on the other hand, there is no reason to count what they have, milk will see them through until they are ready. For some babies being ready means past a year. You just have to make sure that milk comes first and they are getting plenty, don't forget as they get to this kind of age there is more around them than Mummy's boobs and they can forget to ask to nurse.
To answer the last question, it is never too late. I believe that every person needs to be in control of what they eat and if that is taken away, then control will be regained elsewhere. By giving the control to the child you will take away the opportunity for games later.