It's true that some bodega owners would benefit from conversion to a 7-Eleven, but many bodegas occupy too small a space for conversion. My guess is that 7-Eleven's conversion program is designed to undermine the business community's opposition as much as spread 7-Elevens everywhere. I don't see any business associations opposing 7-Eleven. The Bodega Association seems to be silent.
Although business is supposed to about the bottom line, some bodega owners are willing to forgo a bit of profit for the sake of what they have, their autonomy and their relation to the locals. (I know at least one person who will say those owners don't want to forgo exploiting undocumented immigrants, but if 7-Eleven conversion increases profit for the owner, then this can't be a reason to reject conversion. It may be that some owners want to continue employing undocumented immigrants for family reasons or through a tie to some underground human market. That's a deep issue that can only be resolved by immigration reform or amnesty.)