Come on be serious, they're well aware of where DUB sits in the marketplace in terms of a competitive offering. However DUB has a few key advantages MAN can't match.
1) APD in the UK isn't helpful.
2) DUB has preclearance for US flights
3) crucially DUB has a based network carrier with embedded relations with the Irish state, that flies the flag and commands immense long haul brand loyalty.
How exactly can MAN match that in a market where BA couldn't make it work in that market?