Rapidly rising to the top of an industry and being the market leader has its unique set of marketing relations problems.
First, you immediately become perceived as the 800 pound gorilla, trying to muscle out the competition. MS, Apple, GM, Sony, Walmart, etc. have all been there. Just because a business is big doesn't mean it's engaged in unfair or bullying tactics to get there.
Mistakes or poor decisions get magnified across a larger user base. And the larger the user base, the more likely you are to have a visible group of highly vocal detractors. Plus, the larger the company, the less tolerance there is for understanding. How often do you hear excuses for small company mistakes like "They're not Samsung, cut them some slack." But in the next breath you hear "That's inexcusable, Samsung, you should know better!"?
The broader the market, the less you can cater to special interests, especially when they are not profitable. Try and explain to the stockholders why they should allow a small group of developers to modify their firmware, increasing support costs while seeing no revenue generated.
Don't get me wrong. I am not a Samsung apologist. I've had a few Galaxy phones and while they were okay, TouchWiz to me is the Windows XP of Android interfaces. My wife (S3) and my son (S4) love their phones and have no intention of letting me anywhere near them to even root, let alone flash a different rom. They are much more typical of your general consumer and I hold no ill will against Samsung for catering to them rather than me.