I would dispute the idea that Catholics don't believe in having a personal relationship with God or believe such a relationship only exists through sacraments and not also through prayer. It's not an either/or it's a both/and. One can simultaneously believe in the universal Church established by Christ and keep it in sight while still praying on his own often. You can pray by yourself sometimes and in a Church with the collective reach of his followers as well.
There also isn't a dichotomy between personal piety and the greater social ends of the Church. It is indeed possible to stress prayer, morality, and personal piety while serving others. Indeed the social ends of the Church are often met simultaneously with prayer. Praying doesn't necessitate walling ones' self off from society at all. It does sometimes mean a little quiet time and reflection. but even if you spent 2 hours a day in mental prayer (which is certainly more than almost anyone does), you still have 22 more hours where you aren't in mental prayer.
Indeed, I imagine spending a bunch of time in mental prayer and quiet reflection ought to show a person the value of practicing their faith in public and working toward the greater social ends of the Church.
I definitely agree that this is a 'both/and' question, but from my observations it's the hardliners on both sides (though usually the Protestants/evangelicals) that see this as an 'either/or.' Personally, I tend to err on the side of personal piety if only because individuals should make religion work for themselves before they become faithful members of the religious community, but that absolutely does not come at the exclusion of social activity, and vice-versa.
I don't quite get what your question is. though I would recommend Paul Tillich on this issue. a little book, a collection of lectures he gave and then slightly edited/expounded, "Biblical Religion and the Search for Ultimate Reality", contains some stuff on this idea of personalism. to paraphrase what I got out of it, the believer/human meets God "as a person". although God is much more than a person in the sense that we are person, we meet him as people as that is our method of understanding and receiving His revelation.
It's not really a question. I'm just asking for opinions of the spiritual concept.