It doesn't matter what Walt would or wouldn't say. Sadly, he is long gone. If a company doesn't move with the times, then they'll end up suffering and closing down.
Walt heavily believed in corporate sponsorship, that is obvious from the first few years at Disneyland. They also rely on feedback - so many people complained about the coffee they were serving, myself included. The first time I tasted Disney coffee, I actually sent it back, thinking there was something wrong with it. They've listened and given people what they wanted, proper coffee. If people don't like Starbucks because of their brand or their products, or because they think it's over priced, that is entirely prerogative. But I don't drink any soft drink, I don't complain that they serve Coke.
The issue about it not belonging in Main St Bakery seems a little off to me. You're not talking about a small time bakery, nothing was baked in the bakery, it was brought over by truck from a major factory like baking facility at WDW. There was no one making the food fresh out the back. If the items were as popular as people seem to suggest, Disney never would have gotten rid of them. They're about making money. The items might be popular on the boards but in reality, the Dis Boards have very few members when compared to the number that visit the parks.