Logic Pro is just fine. Henry Jackman uses it. John Powell uses it. David Arnold too I think.
They're all good in their own ways and yes, they don't all do the same things. (I'm mainly talking about DP, Cubase, and Logic) It all comes down to what really works for you.
I spent years wondering the same thing and after trying many different DAWs and working with lots of professionals that use different DAWs, I came to the conclusion that it doesn't matter as long as you like the workflow of that particular DAW.
Honestly, I don't think as many people use DP as people have made it sound in these forums. I worked at Remote Control Productions for some time and everyone uses Cubase or Logic.
That doens't mean that DP is bad btw. There are features that I really wish Logic or Cubase would steal from DP.
A lot of the guys on DP are on DP because that's what they started using decades ago, and a lot of them don't want to change because... why should they if it works for them?
It's true that DP has some awesome features for film scoring. Multiple chunks (ie you can have multiple cues per project). You can make your click behave exactly how you want it regardless of what your tempo is set to (which is the same with Pro Tools). I'm sure there are more.
Cubase is in my opinion the best for midi mockup work. The possibilities that you can have with its logical editor are amazing. You can select every 2nd 16th notes and do specific things to those (that's just a small example of the power behind Cubase). You can see multiple controller lanes all at once (and not on top of each other in the annoying way like DP does it - someone correct me if I'm wrong) There are many more but I'm too lazy to write them down...
Logic has the logical editor, where you can do some crazy routing between things as well as midi transformations like Cubase. I remember liking the default plugins.
Yes, a lot of the big guys use Protools but only for routing all the audio there. It makes it easier when you have lots of slave machines that don't necessarily use VEP and/or when you need to give all the mockup stems to mixers (that use PT 99% of the time) Almost no one uses Protools for midi because it's still not as good even though it has improved dramatically in the last couple updates. (I don't use protools much either way so someone can probably expand on protools' midi capabilities)
To summarize, just try them all, find out what you'd rather use composing everyday. Find out which DAW allows you to get your job done in the most efficient way for your particular workflow.
Please don't feel like an infinitesimal insignificant mollusc for using Logic Pro. If that's the DAW that works for you, then that's what works for you.
In the end, no top professional is going to care what DAW you use as long as you get the job done.
However, I do think that having at least an intermediate grasp of all DAWs is very useful. Not only does it make you versatile but it'll allow you to know exactly why you picked your favorite DAW.
Also... there are some composer who like to switch DAWs every once in a while because they get bored...