It would be really bad for their business for sure because the would have lower revenues and profits and the service could stagnate due to a competitor taking charge of that hole in the market. But remember Visa is a centralized service, run by a few people making decisions in what direction to take their company. If you are trying to say that hitting the transaction limit is bad for Bitcoin, it is not. It may be bad for the price or bad for the growth if its user base but this also should be seen as an opportunity on how to improve the technology. Let us all wait for LN and see how that comes out.