It would not be smart to not implement SegWit if/when it becomes part of the mainnet.

Some Bitcoin companies may however not "support" SegWit and would prefer that it not be implemented. My question is, how can a non-mining entity that is part of the Bitcoin economy and/or ecosystem show their support/non-support of SegWit? Even if an entity does not support SegWit they may prepare for SegWit in the event that it becomes part of Bitcoin despite their wishes.