With respect though, it is. May was utterly atrocious, but she has at least had a cabinet post and been prime minister for a short time so you at least have a track record to go against. Corbyn has been in opposition for his entire 34 years in politics, and was largely in opposition even when his own party were in government. He has zero track record of ever having to implement many of the things he talks about, and what's more, due to the factions within Labour, neither do most of his cabinet.
Personally speaking, I'd take competence over any tribal loyalties right now, as it's an incredibly challenging time politically, yet the Tories are low on that (due in large part due to Brexit trimming their available talent pool), Labour are low on that (due to the aforementioned factions within the party), the Lib Dems have been hopeless and the fringe parties are fringe parties.
I'm not sure there has ever been such a paucity of talent in Westminster, so it wasn't an easy choice for me at all as none of them made even approaching a compelling case.