[carmonious]

As you mentioned, companies go out of business or discontinue or change formulations all the time - so nothing wrong with having something else that you know you like. There is a company Valerie Beauty who has just quit formulating mmu to concentrate on skin care I think? and some people who loved her foundation are now scrambling to find something comparable.
I have read on mineral makeup mania before people who have certain brands of foundation that they wear for each season too.