.profile is not loaded on non-login /bin/sh
This is expected sh only loads ~/.profile when it is a login shell. 

From Bash reference manual


  If Bash is invoked with the name sh, it tries to mimic the startup behavior of historical versions of sh as closely as possible, while conforming to the POSIX standard as well.
  
  When invoked as an interactive login shell, or as a non-interactive shell with the --login option, it first attempts to read and execute commands from /etc/profile and ~/.profile, in that order. The --noprofile option may be used to inhibit this behavior. When invoked as an interactive shell with the name sh, Bash looks for the variable ENV, expands its value if it is defined, and uses the expanded value as the name of a file to read and execute. Since a shell invoked as sh does not attempt to read and execute commands from any other startup files, the --rcfile option has no effect. A non-interactive shell invoked with the name sh does not attempt to read any other startup files. 


Of you want bash running as sh to use ~/.profile when not a login shell (e.g. keep current environment) use

env ENV=$HOME/.profile /bin/sh