I tend to agree with you - using in "default" setup with mod_php and mpm_prefork is known to be far from optimal (still fine for blog about you and your cat).
With reverse proxy in front of such setup is - much better in terms of performance. For shared hosting - yet again, may be not optimal if one needs to support multiple system users.
With reverse proxy in front of such setup is - much better in terms of performance. For shared hosting - yet again, may be not optimal if one needs to support multiple system users.