Why is the IRA split into different groups?

The IRA wanted a United Ireland. In 1998 they surrendered and the Dublin government give up its claim to N.Ireland from its constitution as part of the Good Friday Agreement. They totally put the chances of a United Ireland back forever. As far as policing is concerned their terrorism made more catholics keen to join as the catholics started to hate the IRA when the IRA would blow up shops killing anyone inside..They have few members left band split into groups as the remaining few members all wanted to be leaders once Gerry Adams their leadet joined the British in return for a seat at Westminister.