They did, it's a DLC called Genesis (free on PS3 I think). If nothing else at least do that, but I still say it's worth making the effort on ME1.
Some of the smaller decisions and plotlines that aren't in the comic also have effect in ME2, and likely ME3. Even simple stupid fun ones, like Conrad Verner.
The biggest reason, imo, to play ME1 is to feel more...I dunno...committed to the cause and your team. Tali and Garrus are on your team in ME2 as well. Taking the time to develop that connection with them in ME1 likely makes a difference to how you see them in ME2. Garrus and my Shep totally have a bromance, for example...or at least that's how I see it.
I think of it like Band of Brothers without the first 4 episodes. Sure, it'd still be a fantastic 6 episode miniseries, but you'd feel much less invested in each member of easy. Thinking about it, that's probably the biggest difference between BoB and The Pacific to me. I liked the Pacific quite a bit, but still not as much as BoB.