As this is a bit OT I'll be as brief as I can in answering your question.
I think you are right that Unix based OSs tend to require less user intervention in maintenance activities over time. For instance OSX has daily, weekly, and monthly jobs that will run overnight that perform various "cleaning" activities. But not everyone leaves their notebooks on and running overnight regularly so even these automated processes can be delayed or bypassed inadvertently. And these automated scripts don't cleanup and fix "everything".
I'm sure there are a LOT of Mac users out there that don't own any system maintenance utilities and perform no regular user maintenance. I can't say for sure if they have any significantly better or worse overall time of things than those of us that invest in tools and time to perform regular user maintenance. That said, I definitely do see benefits and values in some of the specific things tools like CleanMyMac3 offer (although there are usually other ways to accomplish these either though the OS utilities, Terminal, manually etc).
CleanMyMac3 gets a good review (four mice) in the latest issue (July 2015) Macworld. It pulls together a number of tools I used to buy and run separately at a lower overall price. Note its very configurable, gives you complete control and prompting if desired and only prompts occasionally (monthly or so) to run. Its main areas of functionality are:
- System junk - removes/rebuilds old cache files (can temporarily slow the system but gets rid of any corruption so reduces cascading errors over time), gets rid of old log files (saves disk space and backup time/space, and the MAC routinely logs a LOT of material), removes unused application binaries (where some parts of something may have been removed but other bits hang around), removes unused language files (localizations in apps reducing app size for faster loading apps that take up less disk space), deletes corrupted preference files etc.
- Photo junk - finds and assists in deleting multiple copies/versions of photos (saves space and prevents the annoyance of figuring out which version of a photo you are looking for, need to edit etc).
- Mail attachments - deletes the attachments of emails you've deleted (saving disk space and making MAIL more efficient)
- iTunesJunk - deletes old iOS backups, old software updates, removes broken downloads, etc that usually no longer serve any purpose. Again mostly saves disk space and maybe helps iTunes be a bit less cluttered.
- Trash bins - empties all bins for all drives instantly (avoiding some Finder errors)
- Large and Old files - identifies large and/or old files and assists you in removing them (disk space and clutter saver).
- Uninstaller - just throwing an app in the trash (or even running its uninstaller) can leave bits and pieces of it around - preference files, daemons, helpers, etc and this does a bit better (but not always perfect job) of removing things. Again a bit of disk space and items that can be wasting time in your startup flow
- Maintenance - does a disk check/repair, repairs disk permissions, forces maintenance script runs, reindexes spotlight
- Privacy - clears your browser and chat histories
- Extensions - walks you through various types of extensions (finder, browser, dictionaries, screen savers, login items etc and assists you in removing the ones you no longer need or want
- Shredder - secure delete
This is a relatively inexpensive set of tools all in one spot that helps minimize system clutter, correct issues, and maximize performance and efficiency. Its not night and day, but it does help. And most of these things you could do in other ways without purchasing tools but this makes it regular and convenient. And no, I don't work for whoever makes CleanMyMac3 - lol
