IMO if people still want to use NIP4 let them use it, but in my head this design is wholly unsatisfactory. 

Whether NIP44 is the long term solution is up for the market to decide; the   encryption enhancements and analysis is worthy enough to give the spec a shot at something better than what we have now. 

I don't know if this is going to impact the existing developer base but I'm willing to bet that they are hardcore enough to take it; they're not soft at all. ;)