Well you're still mostly investing in the growth potential of Google's existing businesses. Don't forget that Alphabet still completely owns all the money-making businesses of Google.
Wrong. You cannot have your profits and let someone reallocate them for you too.
You would be right if you owned a controlling interest, but you don't. Because you don't, all the profits of the money-making businesses go where Larry and Sergey want them to go. That's not (necessarily) going to be your pockets. If you owned a controlling interest, you could throw them out if you're unhappy with their performance as capital allocators, but you don't and you can't. So those profits are worth little or nothing to you, both now and in the future, because you aren't entitled to receive them.
> So those profits are worth little or nothing to you, both now and in the future, because you aren't entitled to receive them.
You invest in a company assuming it will increase its value over the time you hold your fraction of ownership. Parent isn't saying you're entitled to dividends, but was observing that the decision to buy Alphabet stock will likely mostly be made on the expectation of the money-making businesses continuing to grow, and only minor-ly on the hope that one or more of the ventures takes off and significantly increase company value.
Perhaps I'm reading it wrong but I didn't see an expectation of dividends in the parent's comment.