It's easy to say the T-shirt is dumb and pretty 'meh' in itself.
But, the fact that this kind of thing even gets made and sold and people are so indifferent to it, is a sign that feminism sill has a long way to go.
Stuff like this is really insidious.
I understand why you've had some of the responses you've had on here OP.
On the one hand, it's a shit T-shirt and only people with no taste would buy it anyway. So forget about it.
On the other hand, I don't think you're being over sensitive to find it A: icky that a baby's t-shirt would talk about dating (gross) and B: that it reinforces the idea that girls don't need to worry about achieving in their own right because you just marry someone rich, right?
I can see where you're coming from.