The biggest issues are/could be

1) what city are we in. Some cities have policies in affect that we can't serve any alcohol on the ground:
Cities where alcohol cannot be served on the ground: CLE, CMH, DAY, MDT, BDL, JAC, EWR, PHL, PIT, ICT, all TEXAS locations prior to noon on Sundays. On Hawaii flights, open liquor carts after takeoff and seal them prior to landing.

2) Catering is late

3) hard to serve while boarding. starts a bad customer experience when someone is swimming upstream

4) Since IFS service only serves pre-departure Water/OJ/Champagne, why should AFS serve something different?

5) Inconsistancy in boarding doors for 757. Some stations (SAN, EWR), they board at 2L, where many other stations board at 1L DFW, ORD, JFK, LGA, MIA. It's so much easier to do pre-departures when you are not swimming up stream dodging bags, being thrown into a pax lap because someone knocked you down.

6) What you consume on the ground, you will not have in the air. You drink all the Bailey's on the ground...there is no Bailey's in the air. Best to save the drinks for inflight.

7) lazy FAs