One of the best features of the last 8th years, by far.
This has been one of te weakest points of Ruby for any interactive app, and clearly one of the most common weak point of any Rails app out there. (It has also been one of my favourite Ruby’s tales for new comers 
)
This “bug” has actually changed the respect we have towards Symbols, and even the way/place we use them, making us pick Strings in a lot of cases or at least forcing us to add dumb validations here and there.
Personally, I celebrate Symbol GC even more than named params or even some of the performance improvements.
Symbols, welcome back!