First proof

Most recipes say 'doubled in size' - my kitchen is cold so I generally make my dough before work, leave it on the worktop to prove then reshape >bake when I get home.  All goes well. 

The resulting bread is fine and has a super soft crumb.  When proofing, It reaches the top of my kitchen aid Bowl but never deflates ( deflation would say to me its gone too far). 

Someone said I was over proving it and it would be better to not let the first rise go so far .  My question is why ?  Second prove always goes fine. 

*I have tried letting it rise in the fridge but then it takes too long to get back to temp, reshape and reproof before baking.

Hope this makes sense, pic is of last  loaf.