Need to keep the party symbol with SP faction
Usually, when the disputing factions cannot come at consensus, then the symbol is not allocated any faction. In the Samajwadi Party dispute that was before the Election Commission of India, the surrender of the symbol by Mulayam Singh faction have effectively ended the SP’s fight in the election. 

If the symbol was not allocated to any faction, the party has to face the serious disadvantages of fighting an election with a symbol that is unfamiliar to the electorate.

Possible hidden reasons behind split
1. Mr. Akhilesh Yadav responded to his father’s gesture by seeking his blessings, and Mr. Mulayam Singh sent his son a list of his faction’s candidates who needed to be accommodated. The SP is not in self-destruct mode. Both factions are playing their cards on the basis of cold calculations, not hot-headed impulse.
2. The split, and the retention of the election symbol, appear to have compensated in some measure for the party’s failings on the governance front over the last five years. Mr. Akhilesh Yadav is now able to seek a fresh mandate on his own terms.
3. Moreover, Akhilesh Yadav can, with some degree of credibility, blame the shortcomings on the party’s old guard. 
4. Also, an alliance with the Congress is now very much within the realm of possibility. Mr. Mulayam Singh was averse to a tie-up, but Mr. Akhilesh Yadav seems to enjoy a better rapport with the Congress leadership. 

The SP only gained from the split, and it might have lost nothing at all in terms of organisational muscle. After giving up the fight for the symbol, Mr. Mulayam Singh does not seem too eager to take the fight with his son to the polling booths, so long as his loyalists got their share of seats.