Ahhhh what a debate!
I for one never understand why you go to the hospital if you break your leg, you go to an estate agent to sell your house etc all because there are people trained to do a job, but yet a sleep consultant is dismissed, even though they are trained to do a job that people need help on.
Babies do not come with a magic help book, that sometimes means we need to ask for help. Whether than be from your mum or a sleep consultant.
I do absolutely fundamentally believe that when a mother considers the 'cry it out' method, they have exhausted all other options.
Obviously no mother wants to leave their child to cry, and it is often the very very last resort, and they have already considered all options because hearing your child cry is difficult, so why on earth would someone even consider this without researching all facts first?
Babies need good sleep to develop, and parent needs good sleep to function.
Whether you choose to get good sleep through co sleeping, through having good sleep cues, through allowing them to cry, there is not enough evidence for any of the methods to make one superior.
Make a decision that is good for the family as a whole, not just baby.