There's no problem installing any browser I like on my Mac.
And as for iOS? Let's see... Google Chrome and, Opera are both available on iOS.
Microsoft (unsurprisingly) doesn't make a browser for Mac/iOS, nor for Linux/Android.
As for Microsoft putting IE in their OS - that was the least of their crimes. The only thing you're doing is proving your rank ignorance in Microsoft's behavior in the 1990's. Microsoft had a nasty tendency to change entire API's so a competitor's product wouldn't run. A popular saying was "Windows ain't done until (Lotus, WordPerfect) won't run." Microsoft was fond of extorting any non-Microsoft software vendors, and creating entirely new Windows-only proprietary technologies (DirectX, Windows Audio, Windows Video, Active Directory... the list is huge) to thwart adoption of standards. Microsoft was (and still is) famously hostile to open source software, even going so far as lobbying politicians to make open source software illegal.
In contrast, Apple supports many major open source projects: CUPS, WebKit, LLVM, and Clang. Apple also has released the source code (ie. their modifications) for over 200 other projects they use. Apple even releases the source for the OS Kernel, and other technologies such as Launchd, Grand Central Dispatch, mDNS/Bonjour, Apple Lossless Audio Codec, and their calendar and contacts server.
Apple is a lot better than Microsoft, even now that Microsoft has "reformed" somewhat. But claiming that Apple is worse than Microsoft only shows you have no fraking clue what you're talking about.