Well it could very easily be argued that for most people, a baseball games lifespan is pretty much the baseball season, so maybe 6 months (obviously some people play longer, but for the vast majority it's the season). So if you pay upwards of $60, maybe even $100 for a game and it doesn't work acceptably as advertised for the first month, that's cost you money, especially if you've paid extra for additional online content for a mode with serious issues. (obviously to most people, they've been able to still find something to enjoy on the game, but people are still well within their rights to feel otherwise)
Also, people can argue that "they don't have to give you anything", but they absolutely do from a
PR standpoint if they want any chance of getting a lot of people to buy their game next year, as this launch will have done them serious harm on that front. This isn't some magnanimous gesture of apology, it's an attempt to buy back some goodwill in the hope of not losing too many customers.
They've done what they feel they had to do and it's up to the individual customers to decide whether this is enough to put faith in them next year.