To my knowledge, RP never left. It was merely diluted because a lot more members came in with F2P and it seems to be a common trend in MMOs for RP communities to be generally small.
If you want to jump into RPing (and I'm not sure what server you used to be on), Landroval is a big RP server for the US/east coast, and Laurelin for Europe. Landroval is RP-encouraged, whereas Laurelin is RP-enforced (names must be lore-appropriate, etc -- not everyone has to actually RP with others, though). A lot of people RP on both.
If you are big on player events, as well, Landroval I know has a STRONG player event base. I can't say what kind of events Laurelin has, as I've never played on that server before (though I'm sure they probably have a lot too, being RP-enforced). Just over a week ago, Landroval hosted Weatherstock 2014, a massive, competitive music concert. In the span of 6ish hours, over 700 people attended, both native Landrovalites as well as visitors from other servers. Weatherstock is the biggest player-sponsored event on LOTRO. I'd imagine it might be the biggest player-sponsored event in just about any MMO. I doubt a single day goes by on Landroval where you can't find some event to attend.
My suggestion would be to create a character on both servers and test them out. See which RP community you like best. If you are worried about rude players, there are bad apples in every barrel, but LOTRO has one of the best MMO communities around.
Welcome back to the game! ^_^
R5 100 GRD Marevayave - Leader of Riddermarked For Death
R8 100 MNS Fayah/100 LM Siennah/100 HNT Dinenol/100 RK Dhurik
100 CHN Alachas/85 CPT Dinfaerien/60 BUR Dhax/35 WDN Godoric
R9 100 MNS Fayeh (alt Wilya) - Lonely Mountain Band @ Landroval