However, Gottesdienst is a journal of the Lutheran liturgical tradition - a tradition that includes all of the above. To set those terms aside to curry favor with the unconvertable champions of innovation would be to undo the whole point of the journal.
Nevertheless, from time to time it is good to review why we use these terms and how they are indeed part of the Lutheran tradition.
First, Mass. Does anyone seriously not know that this is the chief term used in the Lutheran Confessions for the Sunday Communion Service? If you don't believe me, just go to bookofconcord.org and do a search. It's right there, for example, in AC/Ap XXIV "we don't abolish the Mass but keep it religiously." Yup, that's us.
Second, Father. Let's start with Johan Gerhard's Theological Commonplaces: On the Ministry section 26:
And, likewise, [ministers] are called "fathers" (2 Kings 6:21). This title is repeated in the New Testament (I Cor. 4:15; Gal. 4:19) not merely for the sake of honor but also because through the Word they beget spiritual children to God - instrumentally, that is; and in this sense and respect they are said to save both themselves and their hearers (I Tim. 4:16).
Or again, how about the Large Catechism:
Besides these there are yet spiritual fathers; not like those in the Papacy, who have indeed had themselves called thus, but have performed no function of the paternal office. For those only are called spiritual fathers who govern and guide us by the Word of God;159] as St. Paul boasts his fatherhood 1 Cor. 4:15, where he says: In Christ Jesus I have begotten you through the Gospel. Now, 160] since they are fathers they are entitled to their honor, even above all others. But here it is bestowed least; for the way which the world knows for honoring them is to drive them out of the country and to grudge them a piece of bread, and, in short, they must be (as says St. Paul, 1 Cor. 4:13) as the filth of the world and everybody's refuse and footrag.
Shucks, even Fr. Walther himself was known to use the term. And in our day of so many denominations ordaining women, might not a title that directly confesses the manner in which Jesus instituted the ministry have some worth?
I serve in rural Illinois. Folks call the Mass "Church" and they call me "Pastor," or "Reverend," or "Preacher." And that's just fine - those are all part of our tradition as well, but they are in no danger of being lost. The terms "Mass" and "Father" each have something unique to confess and have fallen into disuse and calumny. So we use them at Gottesdiesnst and encourage our readers to get reacquainted with them. Where I serve that means we talk about them in Bible Class - these are good conversations that lead the people into the richness of the Lutheran heritage.