Earlier quoted context omitted.
It would be one thing if it felt like EA had decided they wanted to do a charity event out of the goodness of their heart or at least like the charity was the point of it. As was, it felt more like EA didn't think they could get away with positive PR by actually making money directly from the Humble Bundle but they didn't particularly care since their point was getting buy-in. I don't mean to say anybody should feel…
I'm happy to read that you're complaining about the Humble Bundle's attempt get EA market share. That's as if someone were to complain about Orval trying to get Anheuser-Bush Inbev market share because their lead brewer once said he would buy a Budweiser.
Second, I think you already realise that your analogy is only analogous in that there's a multi-billion dollar company and a much smaller company are both involved.
For example, AB InBev makes up half of the US beer sales with Budweiser and Bud Light being the top two US beers and the Budweiser family is the best selling worldwide. On the other hand, while Valve doesn't release many numbers, it's estimated that Steam has a strong majority of the PC game digital distribution market and Origin's market share is, obviously, lagging far behind.
Also, it doesn't take into account the vast difference between Origin and Budweiser. Origin exists to sell you other products and you have to use the service in order for this to happen. It is difficult to overcome the initial user inertia to get them to join and install the service and to keep it running on their system so that things can be further pushed on them. Once this inertia is overcome there is very little extra resistance to using the service to purchase games. This inertia is also increased because the market of people who would use a DRM-full digital distribution service is not at rest but is rather largely moving along happily with another service. By offering a significant discount on popular games if you start using their service they could convince people to get and run Origin giving them that initial hook.
Further, the Humble Bundle was creating an opportunity to have a significant effect on their user numbers. At 50,000,000 users in July, even if only half of the bundle purchasers were new Origin users, that's an extra 2% of people using their service, and they created positive exposure to many more that may have also joined or may be more inclined to join in the future.
And, finally, I don't think HB was attempting to get EA market share at all. EA was trying to increase Origin market share; Humble Bundle was trying to grow their own service and make some money. (People keep saying the Origin Bundle was "all for charity" or whatever, but don't forget that sending a portion of the money to Humble Bundle was an option that I'm sure some people chose, if only by default.) Again, I don't fault HB for this but it is a noteworthy difference from their prior operations.